Sounds like a great deal, but I see user reviews mentioning the Horror That We Dare Barely Speak Of: The Coil Whine.
If you have bad hearing and/or lucky, I bet two of these would be amazing, though. Selling the coupon would get you some of your money back, too. Probably get AT LEAST $60 on the coupon on ebay, too even if you didn't get the MIR on the second card.
$699.99-60-20 MIR= $619 for 7970 CF plus three new, just released games OR
$699.99-120-20 MIR = $559 for 7970 CF.
Assuming you can sell the games for at least $60 per card. I suppose you could net more if you sold the codes individually. Damn. Almost makes me regret my Gigabyte 670 for $360 (with Borderlands 2) I got a month and half ago. Still, the shadow of a threat of The Coil Whine would likely bother me.
At the beginning of this year, there were individual 7970's being sold for more than the effective pricing of two of these cards now. That's hot. AMD's development of GPU drivers has been nothing short of amazing for the last few months and word that the 8970 successor will be using very similar architecture promises to lead to continued development that benefits the 79xx series.
I'm tempted to sell my 670 and roll the dice...