Look lets be honest, it is early days and perhaps we are all missing a point here. Sony have entered this market trying to flex a technical muscle. A "lets show the world that we are serious here" type of thing. We have to take notice, because all said and done, Sony have effectively picked up the Minolta/Konica baton, so to speak and (rightly) trying to take it to another level. Now, think it through for a moment, Springtide has already stated, that he would of been happier to have had a 12 MP without the noise issue, I absolutely agree. Why bother inventing a car that can do 300 miles an hour if the tyres will only handle 70 miles an hour? I just think that IF your going to pay this sort of money, IF the a900 is going to take your photo's to the next level, then you shouldn't be reading reviews about noise at 200 ISO, should we? really? This on a camera thats supposed to be the flagship. Early days as I said, but I feel more research should of been taken. For my money, the A700 still offers just as much, I don't even own one! just my A350! Ha Ha :-s
I think the problem is that people are comparing the noise levels compared to the Nikon 700 and Canon 5D because they are the same price range. These are different beasts, FF but low MP count - hence low noise.
The noise levels of the A900 are not much different to what the only other 20+ MP FF DSLR gives, the Canon 1DSmark3, which is three times the price of the A900.
People haven't been complaining that the Canon 1DSmark3 only does 5fps or than it's noise levels are poor at high ISO levels, the 1DSmark3 is seen as a ground breaking high MP camera that rivals medium format digital backs in terms of raw quality at low ISO levels, but costing half the amount of a similar quality medium format digital back. Same goes for Landscape photographers, that use 1DSmark3, that only ever use manual focus, never use flash and only use ISO100.
So for commercial, studio or Landscape work, the A900 is just so cheap for the performance that it gives in terms of quality in low ISO performance.
The 1DSmark3 (21MP) costs twice the price of the 1Dmark3 (10MP), and the cheaper camera will blow the higher priced camera out of the water in terms of High ISO performance, FPS & Dynamic Range, but that's not the point. The cheaper camera is not a better camera, it's just for a different market. If you always shoot at ISO 100 who cares about High ISO performance. Buy yourself a Hasselblad medium format back and you'll only get options up to ISO800.
We all know that Sony is behind in advanced AF, so it's no surprise that their first entry into the FF market is based on the stuff that they are good at, producing high resolution sensors, processing data and dumping that data to storage.
As you said, there's no point in having a car that can do 300mph if it can't go around corners. The fact is, to be in the D3/D700 market - you are in with the sports shooters so need fast AF, so there was no point in Sony trying bring a High ISO Monster to market if they didn't have the advanced AF. There is no real market for this at the price point they need to sell to break even.
I agree with some of the comments made on Dyxum, that people expected too much from the A900. People seemed to want a 25MP FF camera, with noise levels and frame rates of a 12MP D3, advanced AF to rival the best of the two major brands, for around $2000 USD. Oh, yes... we also want 100% viewfinder AND a pop-up flash - note that AFAIK there is no FF DSLR that as both, the D700 has 95%.
The basic problem is that Sony are rapidly advancing in their technology, but the hard fact of life is that Nikon and Canon were ahead, and they are also rapidly advancing in their technology. Also, Sony's primary market is currently the entry level consumer. Th A900 is their first step outside of that, and in my opinion until they gain more market share in the lower end market, then the FF market is just their Flagship that will appeal to the few due to a more limited investment (and hence return in investment). They have to have a FF camera to show a path into the Pro market and thats where they want to be, but the truth is that 'Rome wasn't built in a day' - and Nikon have been working for years on their FF entry into the market.
Anyway, I think a lot of people are both happy with the A900 as well as being disappointed. Personally I'm glad the A900 is all what I wanted... it means that I'm not tempted to upgrade at the moment. But, hopefully we'll see more FF models from Sony in a years time - giving us more choice. We can't complain about choice in the lower end market, we just have to wait longer for the rest of the FF range.
Anyway, I'm rambling now...