First the Nexus One, now the Nexus S. As an Android Developer, I'd LOVE to have either of these phones for daily use and development, but that isn't possible when paired up with such a crappy carrier as T-Mobile. I live in the 5th largest city in the US and not exactly in a fringe area of it and yet T-Mobile is absolutely useless here. From my experience going back nearly 12 years, GSM in the US is frequently useless, at least compared to the coverage I get with Verizon, or even Sprint for that matter. Just so you know I'm not just slamming TMO, check out the video below which I accepted great risk to create.
Google, please at least explain why you continue to ruin such a great idea by relying solely on GSM if not provide a CDMA version in addition. Considering the role Verizon had in making Android truely mainstream with the Moto Droid 1, I can't imagine they are making it unreasonably difficult, but if they are, let us know so we can appeal to them.
Please understand that I'm not trying to rant about T-Mobile here (not like in the video anyway), but address Google's choice to use such a small and weak carrier (technology, at least as it's implemented in the US). I know MANY out there will say that's a subjective judgement and want to call me out on it, but be sure to do your research first because I'm willing to bet it will back the empirical evidence I have based on usage in AZ, CA, and OR.