You've not taken a look at the Battlestar Galactica mod have you?
Yeah, actually I have, and it looks amazing! The Battlestar is about 30K polys, but again, there's only one of them. If you add in ten or twenty ships with that LOD you'd have a few problems. I don't know how well that would run on even a high end system with this graphics engine. The engine needs to be capable of easily producing those numbers.
But seriously, would you get decent fps on my computer?
AMD Athlon 64 3000+ 1.8Ghz
ATI Radeon X1900XT 512Mb PCIexpress
1Gb DDR400
Nforce 4 Ultra chipset.
I'd like to think so...the X1900XT is a beast and ought to do fine, but I don't really know how Freespace would do with a million polys on screen.