Well after a few weeks, it looks like COD:WaWii will do really well.
Since the story mode is much better than MOH's, and it includes the co-op play (whereas MOH had no local multiplayer whats-so-ever), I feel COD will be able to sell to the Wii crowd much better, since not all Wii's are online (less than half are I believe), so having a good local story mode + multiplayer is a must to sell to the masses on the Wii.
After only 6 weeks, COD:WaWii has nearly outsold MOH's first whole year of sales in America, and we can only assume it has done something similar in Others (since we don't have any actual data for MOH Others, it's hard to know). I would say a million is basically guaranteed, though it'll probably take all next year to do so. Link.
So though it was a good analysis, in the end, COD Wii will do at least 500k, it's already half way there (and we're actually still missing the week of Christmas), and I'd expect a minimum would be 750k, though I think it'll easily hit a million in the long run. Legs FTW.
And yes, the game is extremely difficult to find for whatever reason. Perhaps all that advertising? It's amazing what a little advertising can do for a game (I am looking at you, all other 3rd parties).