Darkness - IMO, I doubt it'll get near 300k. No game this year thus far has done ~300k yet. Crackdown, Lost Planet and Guitar Hero 2 all were, at max, 280k/wk. I don't think Darkness will beat any of those 3 games. At most, I'd say 250k, but I'm thinking more like 175k should be safe and viable. Remember, there is a PS3 version, so sales might not be as brisk as some assume.
For the 360 baseline sales. I think it's hard to say, as theres only a month between now with post-TB drops and Oblivion, which should also increase the baseline.
Baseline was about ~1950 units on MC before TB. It never got to 1950, but I do believe that was where the minimum was (1050 was the baseline last year).
Trusty Bell should improve it to ~ 2250, and Oblivion should increase it to around 2400~2450. This is after the obvious increases are considered, and should be used as a worst-case scenario figure. Is this number awesome? No, not compared to anything. However, if post Oblivion baseline was indeed 2450, that's more than twice the 360's baseline at the same time last year. Since golden week has been over, the 360 has yet again been selling 2x or more week-over-week versus last year. This doesn't include the fact that the 360 sold 6:1 last week, and around 3:1 this week.
HoV will be interesting. I think it should get ~60k or more. IMO, CoJ is about the worst shooter you can get (in terms of hype and such). Atleast HoV had a demo, even if it sucked.
Back from the dead, I'm afraid.
