The way I see it the article was published just 2 days, so it probably has accounted the first 3 weeks of MGS4 in the 22 millions figure.
Hell, the article might even be including the other MS games: Portable Ops, Twin Snakes, Mobile.
Also, MGS1 and MGS2 were released on several platforms (MGS1 on PS1/PC, MGS2 on PS2/PC/Xbox) - just a bit of info.







