Here is a very useful list of the new/changed features in OOo2.3: http://wiki.services.openoffice.org/wiki/New_Features_2.3#Full_list
I'm marking up my copies of the relevant user guides now, though I don't know when I'll be able to make many of the changes to the files. Any and all assistance from other members of this list gratefully accepted! Michele, I know you're working on some of them; how is that coming along?
--Jean
