I apologize for the refactoring--hate that it surprised you like that :-( - I announced to the devlist a few days back but understand you've been busy coding.
Anyway, I can help: AbstractFormPage has been renamed to "AbstractForm" within the org.springframework.richclient.forms package. Several new features have also been added to this base class.
DefaultRulesSource is still there in the rules package; however, "UnaryPredicate" has been renamed "Constraint" and UnaryProcedure/Function have been collapsed into "Closure".
Several other packages have been renamed from plural form to singular form for consistency, for example org.springframework.rules.constraints is now org.springframework.rules.constraint.
Overall, organization is much better and the design is improved in many areas. We've also introduced a good many new features. Certainly check the archived email from me on the devlist in regard to refactoring last week to get more details on the recent changes.
I hope you upgrading goes smoothley; it took me less than an hour for my app, but then again, I know where things are. Let me know if you have specific problems. I will monitor this thread closely.
Cyboc -- Petclinic works as is: the problem you're related to is jar signing for the client/server issues - see Ben's note.
Core Spring Development Team