I had the livestream open and paused so I didn't miss much, but it was a bit underwhelming. I couldn't tell if you even play as a Spartan either, it looked like ODST gear, but playing as regular soldier following the book storyline...why would Bungie do that.
I'm still hoping IW were joking and that Treyarch made MW2, because they will have just killed themselves. Only Treyarch could rape the PC version so much.