My laptop has:
Windows XP,
Intel Dual Core 2.0 Ghz processor,
1 GB RAM,
Nvidia 7900 GS Gforce Go,
and a 7200 RPM hard drive.
Spore runs perfectly on it, at any settings.
Except for when I'm fighting other ships in the space phase... when multiple ships start blowing up at the same time, the framerate drops dramatically for a second, even on low settings.
Blowing up multiple ships at the same time happens a lot, too, if you ever bother to stop pirate attacks.
I'm not sure if this slow down is normal, but I think a patch will eventually optimize the explosions and get rid of the framerate problem. Or maybe I need more RAM...
Edit: Oh yeah, and I play at a mind-boggling 1900x1200 resolution.