The Radeon HD 4870 X2 with 2GB GDDR5 will retail for $549, if FUD Zilla is to be believed. If this rumour is true then the card will be about $50 more expensive than most people anticipated and more expensive than the GeForce GTX 280 as well.
Nvidia has already dropped the price of Geforce GTX 280 to $499 in American etail and the cheapest one at newegg sells for $469.99 after a $30 mail in rebate.
According to VP of AMD's graphics marketing, the R700 should end up faster than Geforce GTX 280 and with 2GB memory it might look much more attractive than it would look with 1GB.
Nvidia is still enjoying the performance crown with this card but it will be interesting to see will people want to pay $50 to $100 more for ATI’s dual RV770XT card.
The Radeon HD 4870 X2 will likely be available in mid-August but some less reliable sources believe it may already be available this month. The same Asian sources also claim the R700 may be up to 80% better than the GeForce GTX 280 but I would take these rumours with a grain of salt.