It will easily outstrip Madworld... it is just more appealing to the masses (who wouldn't look twice at a game in black and white)
The worst I can see it doing should still see it as a million seller unless it is actually a terrible game (like worse than CoD3).
I think likely first week sales will still be small though (by comparison), probably somewhere between 100k and 200k... I highly doubt it will exceed 200k worldwide launch week. (it would have to have all the best circumstances, like launching on a Sunday so it has a full week or something like that)