In general, I like Sony stuff, but they have abandoned many things in the past. I think it's too early to tell if they are ready to make a serious, long-term commitment. They have their product in a lot of stores but don't seem to be moving many cameras.
The "pro" thing is one thing that Mark and I consistently disagree on (which is OK.) I feel that it's like saying "you're buying your first car, but you may become a race car driver some day, so you'd better buy Bridgestone tires because that's what the Formula One cars use." Someone deciding to truly "go pro" is probably going to want a new camera body and new lenses, as the existing ones may not have the clarity. Let's face it, even the cheapest DSLRs have a lot more functionality than any 35mm cameras that pros might have used until recently.
That "going pro" thing can cost the user a huge amount of money if they ever want to pick up an IS lens, too - I shudder when I see people talking about $1,500 lenses, especially when one of them is considered pretty poor, optically-speaking. IS in the body is a very significant feature IMHO (and most indications seem to be that there's no significant
real world advantage of in-lens IS, you just pay a lot more and have only that lens stabilized). Even ignoring the IS, the cost difference can be very significant. I'm fairly pleased with the shots I got from my last trip and they were done by a $367 camera, a couple $175 lenses, a $125 Russian lens, and a leftover cheap Sigma that I had. In other words, my entire camera system was about what a D80 body costs. If I decided to switch manufacturers, I could sell it all for nearly (sometimes more than) what I paid for it.
I'm not sure that full frame sensors are a serious advantage at this point or that they will be in the future. The theory is sound but the results from the Sony sensors in the Nikons and Canons (and obviously the Sony) are darn near identical at all ISO levels, despite only being APS-sized.
As for listening to feedback, the DPReview review of the XTi seemed to have a lot of ongoing gripes from earlier models, and who was the guy who did the recent editorial about the state of the DSLR industry - who was a Canon guy but bemoaned that Canon has been coasting for a while now and needs to start doing better and listening to the users?
I think the K10D is probably the best example of "giving the photographers what they want" and hopefully the others will follow suit. How's that go, "we're #3, we try harder"?
Anyway, this is mostly academic, the cameras are what they are, no matter what the company behind them is up to. As long as you're happy with your equipment, none of this matters.
I will state that only Nikon and Pentax are actual
camera companies first and foremost, while Canon is "imaging" primarily (like a combination of Xerox and Kodak) and Sony is "everything electronic"... I like the focus.

Pentax also had a very successful DSLR year in 2006 (made good money on them, more than they forecast) and is really riding high. Just look at the number of new Pentax owners we've had around here. They're selling them as fast as they can make them, and the K10D certainly has moved them to the next level. They have their medium-format DSLR coming as well, for the "real" pros.

I don't think there's any danger of them going anywhere any time soon.
(Olympus owners are welcome to point out that that's a camera company first and foremost, too, but Olympus doesn't seem to have their heart behind their DSLR offerings, at least not in the US.)