Possible, but 22 is quite a large gap to close. For Wii you have to consider that in addition to the obvious ones there will be a number of random games that sell very well out of nowhere also, as darth mentioned. I do think that the gap will close some but not until after 2011 when Nintendo has stopped supprting the Wii seriously.
Edit: After taking a look I think there are some more games to add to the list of obvious million sellers on Wii.
Sega Super Star Tennis, Wario Land Shake It, and Toy Story Mania, and Disney Sing It: Pop Star Hits are all very close to a million and still selling. I think they will all pass a million by the end of the year.
Other games coming out this year like the Raving Rabbids game, New Carnival Games also seem near certain to me to cross a million. Then there are a handfull of other games that are sequels to games that sold a million so they have a chance too. So I think it will be awhile yet before the PS3 has a chance to really make up a lot of ground on the million sellers front. But the PS3 has certainly done a good job of selling software so far.
