Hype is all about advertising, which is all about budget. Now, this is not universally the case, as certain media outlets will latch on to one otherwise low-profile game and hype the hell out of it (like IGN and The Conduit, or Joystiq's current love affair with Scribblenauts), though this is true across all platforms.
Wii games generally don't have advertising or budget, and so lack hype. This is often true for many of Nintendo's high-profile titles. They won't feed the media, so the media has no reason to reciprocate (not saying it's any inherent bias there, but you can't hype Spirit Tracks without a trailer, or exclusive interviews, or something)

Monster Hunter: pissing me off since 2010.







