It's the right move. The community was all hyped up about the Halo 2 trailer and then got let down, same with Halo 3. Bungie delivered in the end. As for Reach, it's also a very large gap in the Halo universe that was filled with books. However, a game is -arguably- much better, due to the visuals giving you a firm picture of those events. Also cause seeing five Spartan-IIs charging a Covenant battalion would be badass.
~Hunter
[Edited on 06.09.2009 9:49 AM PDT]