Chip - I'd say the same applies to twentyten - as I'm on record stating in the forums on this site, there was so much completely new stuff introduced in both WP 3.0 and twentyten at the first iteration, that was also completely undocumented and unexplained, that it made twentyten exceptionally difficult to customise (via child or parent theme) for non-professional programmers ... in fact I gave up on it entirely.
The pace of change, and the rate of badly or non-documented additions and changes since WP 2.9.2 has accelerated with every release - instead of being able to come to wordpress.org and find all the essential explanations and how-to that's needed, those of us without a PhD in programming now have to spend days on google just to get to grips with each new feature.
To be honest, several times it has had me on the edge of abandoning WordPress completely and a few times has had me on the point of giving up webmastering. I know that part of the blame lies within myself - I never went to university, did not attend programming college, and do not have the funds to shell out £100 for every programming book that I think I need to bring myself up to speed ... BUT, none of that was a problem before WP 3.0 - and under 2.9.2 I was running both single site and multi-user installs.
Just an example .. some of my sites are still using themes issued pre-WP 2.5 and they're dream themes to work with. However, several would benefit from microformats, custom post formats and types, and custom taxonomies. Can I find a straight-forward "do-this, do-that" codex page to enable all those? Nope.
I've said it before. WordPress needs to slow the development and let the documentation catch up - for everyone's benefit, including those who provide support in this forum.