Hmm, those graphics look fairly on par (imo, it's hard to compare) to the old red steel and rayman graphics. A bit worse perhaps, but beyond anything on the wii so far.
I've seen a higher-quality vid of the pokemon getting blasted with green fire, and it's truly an impressive effect. Not only is the distortion pretty high-res and fills up a good chunk of the screen (never saw anything on that scale with Cube), but it also layers on top of itself.
The effect's definitely an indirect-texturing sort of thing, since it's in the same genre as stuff we've seen on Cube, but IMO it's a lot more than a mere 50% overclock would indicate. Maybe they added a pipe or two, or maybe the TEV's been beefed up to do more effects per pass.