I didn't realise just how horrible the numbers still are http://developer.android.com/about/dashboards/index.html. While Ice Cream Sandwich certainly is catching up, it will probably be 12 months before has a significant market share.
It must be said though that the return 6-month release cycle should help deal with some of the issues, Gingerbread was around as the latest release enough to stagnate. I also don't think Google will ditch the ICS/Holo theming for a while, so ICS should 'age' quite well (not to mention the less then minor changes in the notification window over 4.1 and 4.2 though).