I didn't have a lot of time to check out the new Dumbledore's Army page available here, but I do have some quick impressions. First, I love how Warner Bros. was actually able to fit what sounds like a compilation track that runs for a good while before looping. What better to get you amped for Potter than samples from the franchise's score? Is that a little "Something Wicked this Way Comes" that I hear?
The site also allows you to Join/Login and play a couple flash games. The best aspect (so far), however, is the introduction to Dumbledore's Army. It is too bad that Warner Bros. only focused their attention on the main cast that we already know. The D.A. is full of names we have heard before from a variety of houses (except Slytherin), so why not introduce us to them as well?
Not to be picky, but the D.A. site makes a small error by stating too many "founding members". It was really only Hermione Granger who founded it, and Potter was naturally chosen to lead it. Showing up to the first meeting does not necessarily make you a 'founder' of anything.