Really interesting in depth article interviewing The Big Bang Theory co-creators Chuck Lorre and Bill Prady here :

http://www.collider.com/entertainment/interviews/article.asp?aid=8685&tcid=1

I wish they spoke more about season 2:P

I think they want season 2 to have surprises. One good thing I take from this is I think Penny will have a larger part. If you remember, last season there were several episodes she had a very small part. See this quote from Chuck Lorre :

Lorre: Penny's a far more formidable character than we gave her credit for when we began the series.

Yes, I like the fact that her character will have more depth as well. I'd love to see an episode where Howard, Raj, Sheldon and Leonard talk Penny into the idea to wait on line to see a movie like the Dark Knight, lol and everything would go wrong! LOL.