Watching Reach at the MS press conference was interesting to me. For the most part it looks like standard scripted/interesting shooter fare, but I was intrigued by the Wing Commander gameplay at the end. My assumption is that for the core multiplayer experience, any time Bungie spends on something other than the FPS, but I think it would be some nice glue to the world in the single-player experience, even if it never was the point of Halo.
Mostly, I miss Wing Commander-style gameplay enough that I appreciate having a name like Bungie pushing it into the limelight, regardless of the multiplayer experience cost (because I don't care much for it). I've always felt similarly about Tribes. That the game was absolutely brilliant -- so, so far ahead of its time and still being stolen from to this day -- if only it had a more recognizable setting/developer pushing its concepts out to the masses. It may have been too control heavy, but it's funny seeing Halo and Killzone sporting jetpacks. On one hand, I want to be insulting and call it "quaint," but on the other, I secretly hope that skiing, targeting lasers, and advanced base tactics are also right around the corner.