I just upgraded this WordPress website to version 2.7. release candidate 1 and it works just fine.
There was just one Plugin, the Category Folding plugin that I needed to deactivate, maybe there will be an update for that in the near future.
One other thing I am looking at is to change the Theme to a new one from StudioPress.com an then especially the Church WP Theme
That theme might be some extra work to get it right, but I think it would show even better how your can Build an Website with WordPress
