It's first two weeks of sales are quite comparable to Mario Strikers Charged, which, in North America sold 114k first week, and 64k second week, before falling to less than 10k/week in a few months.
Mario Strikers Charged has gone on to sell 2m copies.
http://vgchartz.com/games/game.php?id=6976®ion=All
That being said, even if it had gotten 300k sales first week, some people would come in and call it a flop, comparing it to Halo and Killzone 2. People are going to again call it a flop, or say sales are terrible when it launches in Europe (no matter what the actual sales are), and again when weekly sales fall to below 10k/week.










