While all eyes are on the Radeon HD 5800 "Cypress" series, there is another series quietly brewing beneath AMD which NVIDIA should be really afraid of. It is targeted at the mainstream market which is no doubt the most important segment for both camps.
Juniper XT and LE will be officially named Radeon HD 5770 and Radeon HD 5750 respectively when launched. HD 5770 card is codenamed Countach while HD 5750 is codenamed Corvette and they both come with 1GB GDDR5 memories on 128-bit memory interface. Juniper will possess all the features of its higher end counterpart like 40nm, DX11, Eyefinity technology, ATI Stream, UVD2, GDDR5 and best of all, it is going to be very affordable.
One of the reason why AMD is not mass producing Radeon HD 4700 (RV740) series now is because HD 5700 series will be replacing it soon and will come one month after HD 5800 series. It will meet head on against the NVIDIA's D10P1 (GT215) series in October so expect a full fledge war then. With a performance target of 1.6x over the HD 4770 and 1.2x over the HD 4750, they are surely packed with enough power to pit against the NVIDIA's lineup. Pair them up and you will get a boost of 1.8x which is roughly the performance of a Cypress card.