His show Monday night, with Madonna in the front row, didn't take a completely new direction from the emerging look of the season, which was already a little softer than fall's warrior. Jacobs just pushed the needle a little farther with lots of ruffles, pearls and even bloomers.
Elsewhere, it's been the bandage look that has been popular - at Herve Leger, of course, where it is the signature item - but also at Carolina Herrera, Alexander Wang, Lela Rose, Nicole Miller and in Victoria Beckham's new collection.
Slashes and cutouts came along with the bandages, adding a little sex appeal at Derek Lam, Rachel Roy and Zac Posen, among other runways. The slashes show some skin, but not so much that it couldn't be office-appropriate when placed on a shoulder or back.
Marc Jacobs reminded style-watchers why he is called a bellwether with his very feminine clothes, which is probably what other designers will present two seasons from now.
There were frou-frou ruffles and pearl embellishment, yet his muse was still a woman with an edge. Think of his customer as the cool, creative type who can find the best thing in a vintage store, or buy Jacobs' blush-colored ruffled jersey dress that mimics it.
Some of his looks went much farther than that - balloon genie pants and pleated bloomers come to mind - but those are for magazine spreads, not the real world. For store racks, he offered wearable jackets that had a hint of military influence and suits that could be the wave of the future, with a stream of ruffles down the jacket that continued on the skirt or trousers.
See photos of Marc Jacob's collection
Zac Posen did things differently Monday. He switched from a nighttime blowout show to a tranquil morning one, a big venue to a small one and - most importantly - he presented clothes you might see someone wearing.
Posen had increasingly focused on dramatic, over-the-top clothes. Remember the whole Midwestern storm theme a few seasons back? Great looks if you happen to be an edgy multi-platinum rocker.
His 2010 spring collection was a complete switching of gears, with adorable, see-through, candy-colored raincoats setting the tone of an upbeat, youthful collection.
Posen hit on the floral trend with a gladiola-print gown with an open back, and a series of finale gowns with sequin flower appliques. He also used the trick of using cutouts to create sexy silhouettes without showing too much skin.
Nothing has moved on the Fashion Week runway quite the way Donna Karan's spring collection did.
The silhouettes were slim, with Karan touting "body skirts" and "body dresses" that fit like second skins, but the light viscose jersey, linen and silk fabrics allowed them a vibe of easy elegance - and wearability. Colors included sky blue, a barely there blush and a lot of neutral skin tones.
If there aren't enough places to wear her jersey wrap dresses - especially the blush-colored, off-shoulder number that was a little reminiscent of old-school Halston - there were everyday clothes, too. A wrap-style skirt suit, for example, is something we should see more of.
If you follow the Herve Leger brand, you might wonder what else Max and Lubov Azria could do with their signature, skintight banded dress. For spring they moved away from the tough-warrior muse toward an artsy-craftsy - or as they say "homespun" look.
The most successful versions of the Leger silhouette were the metallic dresses, the tie-dyes and the braided ones with rows of horizontal fabric loops in place of flat bands. The sexiest were flesh-colored and gave the illusion of bareness without showing skin.
Eyebrows went up when the looks strayed from cocktail dresses: A banded denim jacket doesn't quite have the same effect.
Carolina Herrera showed transporting clothes with exotic rope and raffia details.
There were many textured fabrics, offered in a natural color palette that ranged from redwood brown to light stone. The occasional use of amber, rose and caramel were made to match the "waning light cast at the end of a summer's day," Herrera said in her notes.
Her inspiration was baskets, she explained. That translated well into a strapless gown with a woven bodice and a quartz-colored dress that looks like a checkerboard of organza.
See photos of Carolina Herrera's collection
Thakoon Panichgul's spring styles rode the same ocean-inspired wave as quite a few other collections presented so far, although his take on things certainly had more attitude.
His colors were mostly blues and greens, with a few flashes of pink and scuba-inspired silhouettes. What set him apart were mashups of prints and often edgy mixes of styles on a single garment.
First lady Michelle Obama has worn the Thakoon label on many occasions, but it would be hard to imagine her wearing many things from this spring line.
The cool fashion types in the audience? That's a different story.
Rachel Roy is working it with a smart, sophisticated spring collection that still infused a bit of sexiness for the woman who wants it all.
Can't go wrong with a tailored pantsuit and jacket with feminine flange on the front and slim, flattering trousers. And for the more fashion-forward, there were hammered satin suits and a gray matte crepe jumpsuit.
Roy said in her notes she was inspired by "40s' screen legends, 70s' chic and a return to the 90s' power suit."
See more from the New York Runways
Erin Fetherston called her spring collection "Ladyland" - and it's a place many women will want to visit.
Fetherston's delicate designs were ladylike in the best way - not prim or overly fragile, but delicately refined.
A cherry blossom print in sheer navy chiffon was elegant on a dress with a cape-like back that was belted, like many of the designs, with a whimsical heart-shaped buckle. Plunging necklines were rendered almost demure with ruffled detailing and structured hips on a dress made from floral cloque.
Tracy Reese filled the runway with fun and sometimes flirty dresses inspired by the earthy palette of painter Pierre Bonnard.
The opening number was a sleeveless V-neck goldenrod dress with embroidery on the top and a drawstring at the waist to create a bubble skirt with pockets for a comfortable look. Flirtier pieces included a black sheer drapey dress with opaque polka dots worn over a pink slip.
Other looks oozed class, including a black jumpsuit with spaghetti straps that was cropped just below the knee.
Eveningwear designer Reem Acra nodded to the 40th anniversary of Woodstock in fabrications no hippie would recognize.
The Lebanese-American designer's spring collection was a magical mystery tour from a silky boudoir to a chic hippy enclave - with a stop or two on the red carpet. If the collection seemed riotous, that was Acra's point: She called it a tongue-in-cheek response to "a year of belt-tightening introspection."
There were some beautiful red carpet-worthy gowns and evening jumpsuits - versions were shown in sequins and a garden print, with a finale of beautifully draped white harem pants. But starlets would be wise to skip Acra's '60s flashback.
Zero + Maria Cornejo
The fashions were a little off-kilter at the Zero + Maria Cornejo: A tunic with one sleeve longer and drapier than the other, droopy jumpsuits and short rompers, a dress with a wide black stripe wrapping around the body and disappearing from view.
Cornejo sought to capture her love for the energy of the city with the pull of nature. A black and gray print bubble dress was worn with a wood cuff that cinched only one side of the waist. An airy silk water print dress was half bandeau with a black strap covering the other shoulder and wrapping around to the back.