According to Famitsu and Enterbrain, Pokemon Platinum sold 967,675 copies of the new Pokemon game, Platinum, in just 2 simple days. I would say that we should except this challenge and beat it in America, but that is a wild number. For some comparison, below are some of the top selling Pokemon games in Japans first 4 days sells numbers.

Pokemon FireRed/LeafGreen: 955,337
Pokemon Crystal: 707,580
Pokemon Emerald: 643,987

LInk