Wan to get up to speed on on .NET 3.5 (I know I do!) the Microsoft Corporate Platform Evangelism team released the .NET 3.5 Enhancements Training Kit it has information on:
You can think of this kit as a CTP it's not to where the team wants it to be but there are a lot of people asking for this type of resource so they decided to release it now.
Disclaimer The opinions expressed herein are my own personal opinions and do not represent my employer's view in anyway.