Sorry for the delays and odd behavior today – as with the last upgrade to 3.0, this upgrade wasn’t 100% smooth either. Thankfully it didn’t require total site maintenance, but it did cause some plugins to misbehave. I believe this is all sorted now, and the last post does appear to have gone out successfully and the server errors are gone.
I know you probably don’t care, but it’s cathartic to document a job (not exactly well) done ;).