Of course, you can do that already using the various methods discussed in Turn Your Netbook Into a Kindle. And iPhone/iPod Touch owners can already tap the Kindle store and books on their devices. So what's this all about, really?
I suspect we'll soon see a new wave of touchscreen-powered netbooks and tablets running Windows 7, probably selling for less than $500. Add the Kindle software to the mix and you've got not only an e-book reader (one with a color, backlit screen), but also a full-fledged PC.
Of course, this is just conjecture on my part. What I know for sure is that Kindle for PC is coming next month, and you can sign up now to get notified when it's available.
Funny how this announcement came just two days after Barnes & Noble introduced the Nook, huh? Also funny: no Mac version. Think that's because Apple is planning an e-book announcement of its own? Time will tell.
In the meantime, here's a video that shows the Kindle software in action! (Scroll down to see it.)