wii mote can be used fpr every single wii game, the guitar cannot Hence why GH counts and wiiplay doesnt

In 1 region on a sigle platform, no way.
(>'.')>

Most of your biggest games have a 30% attach rate. To get 10 million in one region would require an instlall base in that region of 30 million.

I don't see that happening for a non-Nintendo platform this generation.

Not unless it's bundled like Wii Sports. Wii Play is in a weird middle ground IMO, but that will for sure reach 10 million in NA. Halo 3 will not make it in NA unless it's heavily bundled for LONG time. I actually can't think of single game that will sell 10 million in 1 region at the moment (except Wii Play).

I doubt there will be a 10 million seller this gen that isn't made by Nintendo. Gran Tourismo might actually.

But 10 million in a single region? dream on

I'd say Gran Turismo 5 but since PS3's sales will never be like PS2's, PS3 is out of the picture in this topic.  The closest one this gen is Halo 3,

The problem with this question is there are few games in existance that have actually managed this feat. If we're talking multiplatform, then GH3 qualifies at 10mil in a few weeks (and it is current gen).

If you lower the bar to multiplatform and at the 7 million mark, even then the only other game that will probably make it is GTA IV.

no but why does only one region matter?

In all regions Gran Turismo 5 will do 10 million

Historically, being packed in is all but a pre-requisite for getting 10 million or more copies sold of a game in a single region (the other options, of course, being multiple versions of a disruptive game as in the case of Pokemon, or a release across as many platforms as possible with a ridiculously popular franchise; that managed to net GTA:SA just over 10mil in America with PS2 and XBOX sales combined).

Having a large install base doesn't even up the odds. Even with the PS2 having about 48 million units sold in the US, 42 million units in Europe, and 22 million units sold in Japan at its peak, has never managed to get enough sales for any PS2 version of a game on it to pass 10 million units sold in a single region. Whereas the NES had all of 60 million units sold worldwide, and it managed to get 2 (and only just shy of 3) games up to that milestone. Two of which were pack-ins for the life of the system, and the third of which didn't make the cut by all of 210,000 units in spite of being a pack-in for a brief time.

Maybe Final Fantasy XIII and GTA IV if you add up the 360 and PS3 totals.