From what I gather, the 7970 fan is identical to the 290X/290 fan in terms of noise. The key difference being that you need 45%+ fan to get better performance, which is obviously not quiet - you never had to go that high on the 7970 but you'll want to with the 290/X for better performance. Anyway, you basically know what to expect...not that it's good or anything.
I agree about the acoustics though. I mean, all these threads complaining about the very same thing, you'd think that the designers at AMD would have enough sense to either 1) design a better blower or 2) have aftermarket cards available on day one. Apparently not, though? I'm scratching my head as to why AMD cheaped out so badly on the cooler. I mean, the card has potential to be 5 star out of 5 star and in terms of price/performance it is, if you don't mind compromising on the cooler somewhat. While the 290 performs disgustingly well at 47%+, it just really is confusing..... I don't get what AMD's thought process was for going so cheap on the cooler.