Just upgraded to Ubuntu 11.10 Oneiric Ocelot, and found that Flash was no longer installed or working. Fixed it by (re?)installing restricted extras, though I was surprised I had to do this since restricted extras was installed prior to the upgrade. Oh well.
Also ran across this interesting post on "10 things to do after installing Ubuntu 11.10". It's focused on a fresh install, and was written based on the 11.10 beta, but everything still applies and may be a helpful reference in the future.
