A fairly good talk, although I wish he had spent more time focusing on what the good solutions are that they currently use rather than what they did that did not work. Most of what he threw out there was fairly common knowledge, but some of the stuff I haven't been exposed to before: replica pools, database partitioning, cache priming for replication updates... so mostly stuff that is specific to MySQL.
I wish he had addressed why they used MySQL over Postgresql though, I frequently wonder why one would chose any db other that postgres.