I'm trying to squeeze a little more available memory now. Those first releases were basically a very first alpha/preview. Now I'll be working on better tuning of these things.
The email about the Nexus S is probably because google/market might be checking for the fingerprint. I left the same as the Nexus S since it's the only oficial 2.3 available right now, so if there's any app specific for 2.3, it would show up on Market.
Battery life seems on par with later Froyo releases... Not much of a difference, if any.