57. Although I might end up a bit low with this guess.

Mid 30's depending on how the line up looks for the last half of the year.

40, maybe a bit more.

hmm... at least 35. Max 60 or so. I could be far underestimating the Wii on this one :P

I would say 30-35, max 40.

The current 19 plus:

Games with a strong chance
Resident Evil: Umbrella Chronicles
MySims
Lego Star Wars: The Complete Saga
Sonic and the Secret Rings (probably very close already, "other" numbers haven't been updated in a long time)
Rayman Raving Rabbids 2
Mario Kart Wii
SEGA Superstars Tennis
Star Wars: The Force Unleashed
Animal Crossing (if it is actually released 2008 in japan)

Games with an outside chance
Pokemon Battle Revolution (only about 130k to go but is only selling around 5k WW a week, most in PAL regions where it hasen't been out very long, a price drop will get it there though)
Dragon Quest Swords: The Masked Queen and the Tower of Mirrors
Pro Evolution Soccer 2008
LEGO Indiana Jones
Ghostbusters
Wii Music
king's story

+ a few unannounced games

probably 28-30 till end of 2008 and 45-50 till the end of 2009.

62 million sellers buy the end of 2009. I expecting lot of smaller games become millions through legs and increasin install base.

I will go with 53

This is the end of 2008, not the end of 2009 guys.

I would put it at around 34 million sellers, I see most nintendo games selling, but not many 3rd party titles.

edit: If the wii 3rd party sales manage to take off as everyone expects(everyone as in vgchartz) then I would see the wii with around 44 million sellers.

55 by the end of 2008. Third party sales will really take off (at least as in selling one million) and some older games will crawl over one million.

Edit: a great deal of the reason is that Wii sales will increase a lot in 2008.