Could 79x0 (and 7870 Tahili based cards) possibly be crossfired with these new cards, or maybe the 280X ?
cj
hard to say, if they redesign the card a bit to much then no normally a yes.
its a smart plan, keep the 7970 that beats the 770 and beef it up a bit more, then add 2 new cards and have a good ball until 20nm.