We have a bit more information about software, but the format has changed for that as well -- instead of each individual version of a game (on each platform, for example) counting as one game on the list, they've been totaled. So Madden NFL 11 occupies one slot on the top ten this month instead of two.
Halo: Reach would have done well regardless of this change (it's at #1, after all, and on only one platform) but now we see games on the top ten that might have been muscled out by the Maddens -- like Kingdom Hearts: Birth by Sleep and Metroid: Other M. Microsoft, never one to ignore a success story, blasted out Halo: Reach's first-month sales numbers: 3.3 million units. It notes that Reach is "only the third game this generation to surpass 3 million unit sales in the first month." The first? Yup, Halo 3.
Update: Hardware sales figures can be found here.
Embrace change after the break.