Are you sure that's a 6800
Ultra for $350? You can't even get a 6800GT for $350 in most places. I'd double-check and make sure it's not one of those semi-crippled ASUS cards or something like that.
If you could get a 6800U for $350, that's a pretty good price. Keep in mind that there are not even any really firm details about NV50/R500, let alone release dates -- I would not expect to see either of them until this fall at the earliest.
Edit: found the card. It does, indeed, appear to be a BFG 6800U OC for $399 with a $50 rebate.
link
(note: links and details are helpful)
If I was in the market for a high-end video card right now, I might seriously consider this.