Its damn neat ..simple to use and easy interfaces...
Newest from the stable of Google...
It follows the principle of simple yet sophisticated from Google...
Built on the No frills based front end, best thing about Google Talk is CPU used while using it which was the biggest failure of yah00 7.0

PROS
1. Multiple Windows Sorted: What i liked about the software is multiple windows (click on the screenshot)..when u r talking to multiple freinds you can talk simulaneously while other messengers force you to maintain multiple windows...
2. Size: Installation File is small (less than 1Mb)....

3. No ads: as compared to MSN and Yahoo...


Cons
1. Keyboard Friendliness: Its not there as was expected from it being part of the google ..so if u r one of those mousephobic, you will hate it

2. File Transfer: Not possible (as of now ...)

3. Chat: Not possible to save the chats (besides copy paste), i like the Message History of yahoo and MSN (Though I dont like XML based History of MSN but it has got its own feature of viwing the chats even if u offline...more about it later ;-))


Final Verdict: Google Talk is out and already famous being part of the growing Gmail....Do check it out at http://www.google.com/talk/