Having some firsthand knowledge about the ads for the Alpha, I guess I can say that we've done a good job, because you're quoting the material ("take your photography to the next level") as if it were your own.
In any case, the Alpha does have a lot of image noise at high ISOs. Because the sensors in some other DSLRs (*cough* Nikon) are manufactured by Sony, you might run into this problem in other cameras, too -- which isn't to say that high ISO image noise isn't a problem in most DSLRs, regardless of who makes their sensors. The Alpha is still a very good camera, and it remains competitive in terms of both price and features (image stabilization and anti-dust, for example) because Sony are trying to position themselves as a strong contender in a market dominated by Canon and Nikon. For those reasons, the Alpha has won a lot of awards and made some "best of 2006" lists on digital photography websites. And rightly so.
Personally, I'm eyeing the new K10D from Pentax. It has all the features the Alpha has as well as weather-resistant seals, and it's compatible with every Pentax lens from the past six decades or so. It's a bit pricier, I think, but the price should fall after Christmas when the shopping rush is over and the K10D no longer seems brand new. (It was released in October.) I'm a bit like you, though, in that I've got my mind set on it, and it'll take a swath of really negative reviews to get me to start doubting. A lot of "experts" have been only mildly excited about it in testing, but user reviews seem to think it embodies perfection.
Have you checked out DPReview.com and Alatest.com? They might give you a bit more of the reinforcement (or dissuading) you're looking for.