I think I read somewhere that Bulldozer will be compatiable with 890 boards.
I think it's rumored BD will be AM3 compatible but it's not guaranteed at this point.
OP can also do this, get something with a cheap m.b. so you don't loose too much upgrading in 2-3 years like say a cheap 1156 or am3 board, I doubt anything you have will be able to take new cpus of the future even if you get the 1366 right now. it's very hard to be future proof just because future changes and by then you'd probably would not care about upgrading as building from scratch will be more economical and yield better results. case in point, the quads on 775 are pretty expensive now even more than when the socket is new.
But with the rate Intel is changing sockets like I change socks everyday, I think any intel socket you can buy this year or even next year is likely to go absolute sooner than an amd socket. For intel this rate of change isn't out of necessity but more from greed, just look at 1156 vs the future 1155!! 1 pin!! pretty unbelievable.