Probably the same reason any game gets delayed, to make it better. It took Killzone 2 4 years to come and its amazing.

The longer WSR takes, the better I'd expect it to be.

Online would be really nice, and if nintendo does really want to get people online, then they would do it. They're not idiots, its just that I'm not sure they really do care about getting people online. I'd also say that it will release during Q2. They will release another killer app for the holidays that utilizes motion plus, maybe super mario galaxy 2, pikmin 3, starfox, or something like that.

Watch for it at GDC. If its not there, then yeah, it basically has to be a holiday title. I just think that its more an issue of Nintendo Co. Ltd., being the ones who have more of a say when it comes out. Remember that the release lists we saw that had it delisted were for NoA and NoE, neither of whom have any control over when this game comes out, but both have more control over Punch-Out!! and ExciteBots, since both are being done by 3rd-party Western studios.

Motion plus will be bundled with EA's Grand Slam Tennis released this July in Europe. This seems to destroy the theory that Nintendo is trying to improve the motion plus technology.

http://www.joystiq.com/2009/03/24/rumor-ea-bundling-motionplus-with-grand-slam-tennis-in-europe/