One question is would you be able to login to AIM using your Google talk? That I don't know! Though AIM and Google clients will be able to chat, it has to be via different chat system. So, Its just that they might be sharing the protocols just like MSN and Yahoo!
Google Operating System (non-official Google blog) has the screen shot - Click Here
Chatting is becoming a lot more easier using a single IM, what if Google Talk shares with Yahoo? will there be the freedom to chat withing the circle:
" Yahoo - MSN - GOOGLE - AIM "
There is need for that, what do you think?