The factories makiing the wiis are probably working as hard as they possibly can at this point, otherwise they would be able to increase production to meet demand. A given factory can increase production only so much, and eventually it is obvious that what you need to do is just get another factory up and running. BUT, this takes a lot of time. It isn't like they are building paper airplanes here....lol . Also, michael pachter the closest thing that this industry has to a guru, has said that nintendo probably wont be able to add another production line until mid 2008
Anyway, unless nintendo has a large amount of wiis that they have been saving, they will be hard to find this christmas. And actually, this leaves a lot of opportunity for MS and Sony to fill in the gap of supply and demand with their own products. A price cut right now would increase demand by X percent. BUT, a price cut during Christmas would increase demand right now by X%+Y%, Y being the increase in demand associated with christmas above the expected normal amount. So, in other words, a price cut during the holidays would do a lot more then, and these other two companies could increase their user base by a lot. Look for some more extensive bundling or a price cut before the holidays....