Don't forget guys that the worst noise for the 6990 comes in Furmark which 99% of review sites tested with powertune unlimited and the OC bios(rightly I might add), however most also tested the 590gtx in furmark with the furmark limit in place. Anandtech suggest 70dba in furmark but significantly lower in actual gaming, the 590gtx comes in as quieter everywhere, but in games its not monumentally quieter, its just the daft Furmark comparisons that make them seem miles apart.
Make no mistake, AMD screwed the pooch on the fan, bigger proper fan would mean AMD would have had the unquestionable king of cards, lower power(again ignore furmark unless the 590gtx is tested with the furmark limit turned off(not sure Nvidia have even made it possible, I know it was ont he 580/570/etc), faster, cheaper, with a proper fan it would have been quieter and cooler on top of that, and with better xfire scaling it would have been such an obvious win for AMD(still is, just narrower).
Also worth mentioning so far I've seen little to suggest the cores are dying on the 590gtx's, it seems to be the power circuitry, nothing more than that, but thats still a huge issue. If some are dying at stock, then Nvidia have a massive massive problem coming and bad press with RMA numbers potentially being high in the future. I'd expect the 6990 to have higher RMA rates than any other AMD card but, dying in reviews in a few days of testing, thats really not good. If the mosfets are blowing up very quickly, and thats the real issue, with a fairly small bump in voltage, you wonder how hot they are running at normal settings and how long they'll last.