It's just like the old "Buddies list" - but you can click on someone's icon on your "friends list" in your own profile, and that takes you immediately to that person's profile page, where you can quickly send them a public or private message. Public messages appear just on their profile page, though, so if they answer, you'd have to check back on their profile page.

Debbie, we made a new upgrade a few weeks go, check down in Town Hall for a bunch of other new features - and explanations!