Case: Dell Vostro 200 case(getting thermaltake v9 black edition in a month)
Motherboard: Foxconn G33MO2(getting ASUS P5Q Pro LGA 775 Intel P45 ATX Intel Motherboard in a month)
Processor: Intell core 2 duo E8400 3.0ghz
Memory: 4gb PNY 800mhz
Power Supply: Rosewill 630watts
The gtx 275 is not released as of yet and there really are not any good reviews comparing them. You will get a lot of fanbois on the forum about the 4890. Seems to be a great card at a good value, but till the gtx 275 is actually released it is hard to decide.