Even though WiFi is getting faster, it would still be way too slow to play a Wii game - I'll let you do your homework, but I will point you in the direction to start your search: Look up the transfer speed of a standard DVD drive (particularly the ones used in Wii's), and compare that to the fastest available transfer rate of current WiFi technology.
Now think about any Wii games you have played that still have even a momentary load time, and consider how much faster DVD (and USB) transfer rates are. If you take the ratio of transfer rates, and apply that to any load times, you'll find that trying to play through WiFi will have you spending far more time waiting for data to load than you'll get to spend playing the game.
Then, consider the fact that these pauses to load more data will occur almost constantly - try playing a game one frame at a time, with a new frame every few minutes... It would be a lot like watching Toy Story as they made it, which took a couple years for that hour and a half of film (and that was with several computers rendering frames simultaneously)
I may be wrong, but I think the WODE will only be able to pull it off by preloading (like buffering a streaming video), which will imply additional on-board memory (I can't remember how much ram the Wii has, but I don't think it was nearly enough to do the job).