It's not all about AAA titles like MW2
In my opinion one of the best titles for the Xbox is 'Splosion Man, the gameplay is out of this world and is brilliant for having the guys over and a gamefest, but the graphics aren't the best and is still only a 2D scrolling platform.
The Wii could handle graphics like that no problem and already does, so rolling out the same sad old excuse of "The Wii can't do MW2 so it's rubbish" just doesn't hold water.
Maybe if I told the same Xbox user that he couldn't run his game at 2560x1600 or at 100fps his console is a joke compared to my PC he would agree with me? Of course not. Simple fanboiism at it's best. The Wii has carved out a market and not just a niche market, it has appealed to the wider majority that exist beyond the teenager/geek 1337 console tard model to the millions and millions that just want to play fun games.
The fanbois always point out the worst Wii game that can find to compare it against the best Xbox game to highlight their point, whilst ignoring the huge array of absolute stinkers that exist for the Xbox and the fantastic titles for the Wii - so let's do just that:-
Xbox 360 - Leisure Suit Larry : Box Office Bust
Wii - Tatsunoko VS Capcom : Ultimate All-Stars
On that basis I can easily say that the Wii is better than the Xbox 360, but Nintendo hasn't got into a pissing contest with the other consoles on trying to appeal to the testosterone and hormones market, they have a solid market of fun, family oriented games that extend to all sectors of the market and therefore have totally side-swiped the competition.
Microsoft and Sony know that they have missed the boat otherwise they would not have invested in motion controllers, the 1337 gamers will still play shooters but the market will extend and they will become increasingly outnumbered and viewed as a minority in good time.