Effective immediately, you can now create e-mail aliases which are completely different than your primary e-mail address. When you create this alias, you can specify where these mails should go, so you can automatically file them in a subfolder of your choice.
This is better than the previous Hotmail solution (and, I should point out, the current Gmail solution), which was to add a plus sign and extra characters to your primary e-mail address. If your address was email@example.com, for example, you could create firstname.lastname@example.org for all your newsletters. But that address didn't fool anybody, least of all the bots. It's too easy to scrape away the extra bits to reveal your actual e-mail address.
So now, you don't have to tie your alias to your main e-mail at all, making it truly untraceable back to you. Microsoft will allow you to create 5 aliases per year, and a 15 aliases in total.
To create an alias, point at the Inbox heading and click the gear icon. Then choose Create a Hotmail alias. That's it.
More on BNET: