Meh it isn't much different to me, I really only ever used two or three things in the last one... The main page, my answers page and my messages page. Which are still basically the same now, although slightly jazzier. I don't really have an interest to discover all the features with it as i'd never use them myself. I don't believe there is a chatroom that i've seen listed so far... although I know the messaging system has much more of a 'live chat' look and feel to it.
Not a fan at all. It's new so hopefully it's just a learning curve thing. But I don't find it easy to navigate through. I think another thing that will be a down side is there are way too many categories to put questions now. I think the old format with the 8 or ten choices was far more practical.
I don't know if I like it just yet it's kinda complicated to find the subtitles you want to follow it's kind of like Twitter the way you follow certain things or like Y! Answers for me I'm finding it complicated but I think I'll get use to it lol