It can improve the social site when people use text chat. And really that's what you use 90% of the time, it's just better then voice. Also voice not works between two scene's
Now it would nice that you hear a beep when you get some IM message or local chat message. keep both separate with turning the sound on/off.
So you can have a beep on IM but not on local chat.
It also would be nice add on in case sound is off the have a flashing taskbar button. This way people know when there's new message. Right now people not see it quick enough.
It's still in the current version very hard to see who did send the IM message. Still need to check every name. Can we not have some indicator behind the name who did send the message ?
I hope someday we can move windows. Because the chat window complete bottom left is the most bad place for reading chat. (same in SL, but there i can move the window) I like to see the chat on the other location.