There are a ton of comments on this post already. My two cents is that having previously lived between First and Second avenue, I think the new T line is much needed to reduce congestion and prevent the lazy (i.e. me) from having to walk to Park to catch the subway. Unfortunately, it's still ten+ years away.
I do agree with some of the comments, including perceived lack of express tracks, lack of extension into Alphabet City and lack of attention re: expanding cross town subway options and subway issues in the other boroughs.