This is an interesting post. You say 1 in 5 WaW owners are avid online players, correct? I'm thinking it's closer to 1 in 3, but it will be interesting to see how much the game will sell in its first 2 weeks (I myself am doubting it will break 100k even in 2 weeks).
Well, it's not like hardcore online gamers would buy this for Wii...Single player would for most people be the first station. Hell, I had to take a few days before I started Mario Kart online.
Plus I don't know how the online system works for this game. You might even only see the acounts of a certain region.
CoD 3 sold more on Wii then on PS3, and while I don't expect that to happen CoD:WaW will definitely do well. It will certainly sell more then CoD 3, which was a crappy game.