A couple days ago, Jenstar posted a thread at WebmasterWorld named Review of the Google AdSense Webinar for new publishers. The Webinar was specifically for new publishers, so I am sure it bored many of the publishers that have some experience with Adsense. Jenstar does not that:
Confirmation from AdSense of the top three ad unit sizes are-
1. 336x280 large rectangle
2. 300x250 medium rectangle
3. 160x600 wide skyscraper
AdSense plans to release new languages each quarter.
The full transcript can be found under the name Google AdSense Optimization Webinar.