Well, I tried it last night. Didn't get that far because of family issues that took me pretty much right up to raid time for my main.

I did copy the WoW folders into unique installs for each alt. And created my main and 2 alts for now. I took your advice and went with a preist + 2 warlocks. I went with undead because WOTF is just too powerful.

I was able to get 2 instances of WoW running on the single core machine (7800GS agp) pretty smoothly. Set them both to 800x600. I ran windowed mode and re-sized the windows to see *most* of each. The active window would run at 50-60 FPS, but the inactive window would drop to 15-20 FPS. I don't see this as a problem. I got a Keyclone liscense, but didn't try to set it up yet, as this machine is prolly going to be my main. And it was raid time.

After the raid (first time seeing Void Reaver, lots 'O wiping), I tried to get 2 WoWs running on the dual-core rig. This one has SLIed 6800GTs. Graphical problems when I opened the second WoW. I tried to disable SLI in the Nvidia drivers, but my computer bluescreens whenever I open the Nvidia control panel. SO today I will resolve that and try again. With luck, by tonight all the 'game' related stuff will be taken care of and I can get to setting up keyclone, keybindings and macros.

Thanks for all the advice so far...keep it coming.