I don't think any none-BTO graphics card will support ADC anytime soon...
Otherwise, I read somewhere that until the Radeon is officially released and in the channels, ATI will not announce their trade-back program. I'm still waiting and have my ATI rebate found at Outpost ready as soon as the program is announced. I figure it'll run for less than US$200 after all the rebates, which is a good deal, albeit no 64MB DDR version and slightly slower DDR RAM performance...