Just about all of the 40 or so apps on my phone work with 2.3, save a few that have been updated in the past few weeks to work.
The reason why I generally try to avoid restoring all my apps going from OS version to OS version with the exception of games is that stuff can go wonky with framework changes and such. It's not that hard to go with a clean start except for my games. I could probably restore and have nothing go wrong, but I prefer to be on the safe side.