Nexus S might look more appealing when an LTE Nexus comes out along with LTE pricing... Though hopefully you could still use it on 3G/HSPA+ only without paying for LTE... (obviously this is most applicable for ATT customers)
The rationale behind the NS is just too curious to me. The purpose of the phone (ostensibly) is to be the reference phone for designers. However, it was long known before the NS was even hinted at that dual-core CPUs would be available in 1Q of 2011 (actually, the rumor was for their availability in quantity before the end of 2010). So a reference phone should, it seem, have the most updated design for the software writers to use.
Instead, the NS is a good, but not great, phone, with some significant feature omissions and a processor which was at the cutting edge for about 15 minutes following the release of the phone, long since replaced by dual-core beasts about to hit the marketplace.
My guess is that Google was determined to bring Gingerbread to the public before the end of 2010, and the time required to design and build the NS didn't allow for time to build a phone with dual processors (and perhaps tweak the code to optimize for the CPU). Then, as the release date approached, it was increasingly clear that Gingerbread wasn't ready for widespread release, but the marketing participation of BestBuy was already locked in and Schmidt had made the announcement that the NS and 2.3 would be out before the end of the year.
The NS owners I have talked to seem underwhelmed by the feature set of Gingerbread (their phone has NFC and nowhere to use it, for example), and have basically paid for the opportunity to help Google beta test 2.3, which wasn't what they signed on for when they paid $500 for the phone.
Unless Google forks Honeycomb to the Android phones, it would appear that Ice Cream Sandwich will be the next major release for the N1 after Gingerbread eventually makes its appearance. Perhaps ICS will not only provide a significant feature set update but also come riding with a new reference phone; maybe then I'll be tempted to upgrade from my N1. Until then, I am perfectly content with N1 and Froyo.