ummm, actually… since mac is now on the x86 platform, he is technically correct. Aside from the mainboard, they are pretty much the same hardware wise. Just about anything you can get for PC, afaik, you can also plug it into a mac with no real problems as long as the OS has drivers for it.
edit: if windows will run on a mac natively (no emulation), then the hardware is obviously the same, or very similar