there arent really any am2+ boards readily availible yet. at least no rd790 boards. gigabyte's GA-MA790-DQ6 looks pretty interesting, thats probably the one i will get. that or the DFI. i'll use my 590 for awhile, though. the overdrive utility for amd that will come with the new boards looks awesome, too.
i'd wait a little bit for the am2+ mobos to be released.