This is a minor update:

Beta2 update (ContentManager)
Minor bug fix with TextBoxes not deleting their backgrounds.
Initial stab at compiling for the 360 (by #ifdef'ing references to Texture2D.FromFile so that they can be removed easily)
Temporarily remove CollisionDemo since it's acting up under beta2 (there are reports that it was acting up under beta1, but I was unable to repro them...) This demo will come back once these bugs are fixed.