If the PS3 gains a significant foothold in Japan, it'll bring a lot of niche games to US and EU shores -- namely JRPGs.
Since JRPGs don't require a lot of CPU horsepower, typically (GPU is another story), the PS3 would be like an uber Wii, as far as small Japanese devs were concerned -- a 3.2 GHz CPU plus a 550 MHz GPU with a truckload of memory, compared to the Wii at ~0.75 GHz CPU and ~250 MHz GPU.
Without the SPUs in the picture, the PS3 is no harder than the Wii to develop for, really, except of course for the fancy texture work if you want to use the spiffier GPU's best features.
If there are ever enough PS3s in Japan, you can believe there will be a lot of JRPGs for it -- with the SPUs out of the picture, as I said, the "HD cliff" becomes much less difficult to climb. Many of the PS3's release titles didn't use the SPUs, and their dev time was greatly shortened... which probably also means they were a lot cheaper to make as well.
