Ubuntu 12.10 comes out with an apparently slower Unity desktop. Even Gnome Shell seems to have suffered. Maybe time to give BFS scheduler a go?
In any case, Ubuntu 13.04 has been christened "Raring Ringtail" whatever that means. Let's hope Mark's "mobile metrics, things like battery life, number of running processes, memory footprint, and polish the rough edges" means we'll get a faster Ubuntu release come April 2013.
Of course, I'd settle for just "memory footprint" and "polish the rough edges" actually landing in 13.04 instead of partially like so many things in Ubuntu of late.