I would say at least 4 but as high as 6.

 I figure

Halo 3

Stranglehold

Bioshock

Madden 08

after that it should be mainly nintendo/ds with possibly heavenly sword.  What do you guys think?

I assume your talking about America. Skate might make it in, thats probably it though. Wii sports and Wii play will be in there, probably Metroid Prime and pokemon. More brain training maybe.
Thats my guess.

Looked at the numbers and changed my mind. Here is the top ten:

Halo 3           - 2.6 mil     (360)
Wii sports     - 396,000  (wii)

Bioshock       - 280,000  (360)
Stranglehold - 266,280  (360)
MoH:A           - 247,537  (360)
Wii play         - 224,00    (wii)

MP3               - 208,000  (wii)
Madden         - 193,000  (360)

HS                 - 184,000  (PS3)
MBT               - 163,000  (DS)

so 5 360, 3 wii, 1 ps3, 1 ds 

Yes this would be for American sales and what the NPD will have for their top 10.

American NPD is 5 weeks........

So we won't see it until about Oct. 18th or so?

@Adam540

Wii Sports isn't reported in software sales for NPD. However many Wii's sell in NA, that's how many Wii Sports sells.

Halo 3
Bioshock
Madden
Strangehold

I wish wish wish Eternal Sonata or Blue Dragon would show up, but ... it's wishing. 

didn't realize wii sports didn't show up, in that case, skate for the 360 will make it in instead, but then maybe i'm wrong cause i calculated it all assuming sept was a 4 week month

HALO3
MADDEN
STRANGEHOLD
SKATE
BIOSHOCK