Sure... Well actually not, but its not a big deal. You can just get 2 USB tuners...
(On a side note - some PCI-e twin tuner cards are in fact just 2 USB cards put on one PCI-e card.. Just like the Tevii S480, which is two S660 tuners on a card..)
I run the Tevii S660 USB tuner card (on i868 hardware) - It is working very reliable and stable for me...