The setting and "artstyle" is pretty much 1:1 FFXII, so comparing it with that is quite viable.
And MH3 is by no means a low budget game too (well FFXII was probably the most expensive PS2 game, with its four years or what in development).
And, in my opinion, this looked only slightly better. But, FFXII is one of the more impressive PS2 games of the latter half of PS2s cycle and the Wii is still pretty much "untapped" (although all GC knowledge should apply too, so pushing the metal should've happened quite early too) for what it's worth. But since the Wii is supposed to be 2 GCs duct taped together, it looks quite bland. I mean, as I said earlier, the GC was faster than the PS2, and now the Wii is twice as fast... it should produce MUCH better graphics than this. Especially for a game, that will surely sell several million units in Japan alone (see the PSP titles).
The textures were good, and the details in the characters/monsters too, but the overall picture didn't look much more advanced than FFXII, which has probably 3 player characters on screen plus a huge endboss like Tiamat, which alone fills the whole screen.
I don't know... I guess the developers/publishers see, that graphics on Wii don't matter and thus see no need to push the hardware to the limit, like the PS2 was it its day.