God, SC4 was so much fun. I wonder if I can get it working on my 64-bit Win7 box. Last I checked, it had some problems with that.
There's no problems at all running it on Win7 x64. And you should see the amazing custom content that's still being developed. Not just the thousands upon thousands of buildings; but an entirely new highway system with 2-10 lanes and completely custom ramps, tile-by-tile canal systems, or the incredibly detailed modular airports- can cover an entire large city tile with just an expansive airport; I released an entire plugin that's just tiles to make lines on the taxiways. Other modular sets let you construct expansive seaports, military bases, and any kind of landscape you can imagine.