You don't need to sell 100 million console units to have a lot of million sellers.
So far this year the Wii has been unable to close the gap with the 360 and the next 3 months releases look more in favor or the 360 than in the Wii in term of additional million sellers.
Like I said earlier in the end the Wii will dominate the 5 million+ sellers but the 360 will keep the lead for million sellers.
The PS3 won't be able to catch the 360 as 99% of the multiplatforms titles selling 1 million+ on the PS3 will do so on the 360 too and there is no way Sony will release 30+ first party million sellers than the 360 ( Sony will release more but not that much more...).
PS : The Wii will sell a lot more software but the success of its heavy titles actually does not give it the edge in this fight.
While Mario Kart sells 10 million units the 360 users tend to spread their purchase accross more titles resulting in less total software but more million sellers...