Actually, it works but with limitations. No shock there. It turns out the PV-149 CCTV capture card I'm trying to pass through presents each channel as a separate Video and Audio device. What that means is I end up with 8 PCI devices that need to be extended. I'm running into a problem that might be specific to VMWare or VT-d where I can't passthrough more than 6 PCI devices. This isn't too big a deal as I don't use the audio channels but I'm worried now that the missing audio is causing some BSOD's. I'm still investigating.
Otherwise, vSphere is running pretty nice.