The latest version adds some nice features such as "send as" functionality (so now my email address doesn't look like @hotmail.com).
It also gives the UI a bit of a make over, which I quite like.
Its also designed to be more user friendly for new users with tool tip support built in.
I also noticed that you can now send emails to your groups in Live Messenger (create a group in Live messenger and then communicate with them as a group).
If you dont see the update yet, dont panic, they are rolling it out in a staged manner, so you'll get it in the next couple of days.
Dont forget that you can also get the desktop version of live mail which also does RSS and news groups here.