Also, I merged a bunch of ideas together and probably rushed that reply. I'm horrible at posting to forums like this because I almost never get up the nerve to do it.
Anyway, if Android was more available (i.e. if the O/S was adopted by a major cellphone manufacturer like a Nokia or Motorola across many different models on multiple carriers), and I could have easily got my hands on one, I would have bought that instead. But as far as I know its only available at T-Mobile, and only in the form of the G1, and was only maybe available at this one T-Mobile store that was quite a drive from here. Many other phones are easily available within a very short drive, so that's what I ended up with.
I'm guessing at least half will be available in the U.S. I'd also wager that, if not by the end of the year, then at least by next summer, all major carriers in the States will have multiple Android phones to choose from. So things are moving in the right direction; when you're ready for your next phone, I think you'll be very pleased with your options.
Openness? Why do I still have to jailbreak and unlock an Android phone, when it is so open? (Rhetorical Question)
Price? Yes, check if you want phones with really bad battery lifetime (so far, let's see when a decent phone comes out, I might reconsider).
Btw, is it true that you can only use the phones if you have a google account and that there are several phone home features in the phone?
Have you not heard of Android? Developer friendliness? Check. Openness? Check. Support? Check. Price? Check.
Google is spectacular in all of these regards. Android is open source, and Google is throwing serious weight into making things extremely easy for developers. It's not without its problems, but I give it an 'A' in every area you brought up.