Ok, let me see if I can help (without further confusing you

)
I think you mean ROM rather than kernel, and I'm sure he'll release a 2.3 ROM when it actually becomes available (only the SDK has been released, not the source code). It will most likely be compatible with SPRecovery as well. I'm actually surprised that you are getting the OTA notification (which isn't for gingerbread {2.3} but actually, 2.2.1 which I think SS4.9 already has) since most ROMs block it. But good call on not accepting it, it will most likely break root.
Anyone else feel free to jump in with other opinions or corrections ;-)