Modern Warfare 2 sales plummeted in the UK after the game's first day of availability. As you already know, the game moved 1.23 million copies on its launch day -- however, according to Chart Track's calculations, it finished off the week with a paltry 1.78 million units (for £67.4 million) sold. With pathetic figures like that, you know Activision's got to be feeling disappointed.
Other UK chart staples (Wii Fit Plus, Wii Sports Resort, FIFA 10) all maintained their top 10 ranking this week -- though the list had two unfamiliar visitors who vaulted to the top of the charts on the back of a new 360 bundle: Lego Batman (which jumped from 14th place to 7th) and Pure (which sprung from 23rd place to 9th). That's quite a comeback for these two titles, though perhaps they would have fared even better had they been bundled with copies of Modern Warfare 2 instead.
Source -- Modern Warfare 2 Smashes All Records [Chart Track]
Source -- All formats chart [Chart Track]