Yesterday I pasted in a YouTube URL into Google Talk LE and it took that URL and mutated into a specail link to Youtube with a picture of the video, play button and go to page button. Pretty cool.

That's been available in the Google Talk Gadget for a couple of years:

http://blogoscoped.com/forum/88808.html

(I'm pretty sure Google Talk Labs Edition is based on that as they're so similar.)