That's bizarre. Are you sure the other wii games are running in 480p for you and it's not some placebo effect? You are using the component cables correct? Maybe you need to buy the monster cables.
Did you try mario kart to see if that brightly colored game also looks correct to you?
As for the other part of your post, based on the "early" you used in your comment, you should check the resolution thread. Many games run the gamut of resolutions from 480 (scaled down, not sure of native) to 1080 (native or scaled up).
It amazes me that, let's take Halo 3 @ 640p as an example, that 640p = 480p. What's even more amazing is that, taking the same game as an example, being 160p from standard def and being 80p from hardline 720p warrants the very same vitriol from the same people, even though it's significantly more fully featured pixels across the board than what the previous gen could offer.
Oh well, roll on subHD bandwagon. Roll on.
By the way, Sony was throwing around all the TrueHD talk when their system hadn't launched yet and the 360's HD initially topped out at 720p. "TrueHD" used to mean 1080p if. Usage of TrueHD and FullHD was all the buzz with the hype/marketing surrounding the PS3. Anyway, not all of us split hairs with native vs scaling, but it was required by many to keep the sniping going on each side.
I admire the fact that I set 1080p once in the 360 dashboard, and the rest is taken care of such that my HDTV doesn't blank and hunt for what resolution is coming in as I switch content. I like that I can tick 720p and 1080p in the XMB on the PS3, but it's still annoying that dependent on the source, i'm not necessarily getting the best output from the system unless I tinker with the XMB. You'd think microsoft would have marketed the fact that you set your display once and always get the optimal output (believe it or not these systems have great scalers) without your display doing the resolution dance. Oh wait, they did to some of us.
Anyway, I had to connect the Wii to my HDTV for the holidays for all the folks that came into town. I didn't see the big difference between 480i/p, but that could just be the effectiveness of my TV's scaler. But basically, if grandmaster says it's 480p, then it's certainly 480p.