Quick update. Threw together a quick triangle stress test. Flat colored planets, 131k triangles each. I can throw 10 of them at my ATI X1600 and it can still maintain 60FPS. This gives me a total triangle throughput of just under 80 Million per second, and it's a triangle list so unless they are caching results (which they can only do once per planet since each on is in a different position) that's a total vertex throughput of around 240 Million per second.

TPS = Triangles per second. stresstest.jpg