First of all, there's a downloadable widget for your desktop, in the form of Batman himself or The Joker. Also, there's a tool for creating your own custom wallpapers, if you're into that sort of thing. Then, there's the usual: screens, video (the E3 trailer you saw already) and other miscellaneous goodies. Keep an eye on the site for the new content, which is supposed to be live right now, but wasn't when we checked.
On top of that, there's also a new Facebook group for the game. That is, if you're into the whole social networking site thing.
Source - LEGO Batman website
Source - LEGO Batman Facebook group
