[Catalyst] Session/Authentication/Authorization for legacy + Cat

[Ashley Pond V]

I'm working on some session code which I'd like to be able to use  
with legacy code (non-Cat) and Cat. No problem. Apache::Session 
(::Flex) and CGI::Session both have Cat plugins so either one will  
migrate fine (seems like CGI::Session is the winner; deeper controls,  
same divers backends, active development, no table MySQL locking or  
DESTROY squirreliness). Yay, team!

For authentication/authorization though I can't find a(n obvious)  
path for both legacy and Cat. I love the Cat plugins, btw. Is there  
is, or is there ain't a way to write authentication/authorization  
which is going to work (at least in the backend) for both?

Any tales from the punchbowl on the topic?

Thanks!
-Ashley