I disagree that it'll be a flop... thats exactly why they spent ten years making it - the first couple of versions they were making, they didn't like. They're obviously trying very hard not to make a flop.
I don't think it will have the depth of Half-life & Co, but it'll sure as hell be a Halo 3 beater (not in terms of sales, in terms of gameplay). Well
This game best be histories greatest contribution to human culture and the cure for atleast one typre of cancer.