This does bring up an interesting point about flow control.
Even when you're not using a wizard-style intereface, there will be
times when the application needs to have a slightly more complex
behavior than a simple redirect or render. Say, a chain of redirects
that happens only when the user first signs up.
It seems ugly to embed this across several actions and controllers.
I've been thinking about the possibility of separating program flow
from controllers / actions. To make a kind of DSL that says, "under
these conditions, follow this path"
Have done some work on a plugin - nothing that's release-worthy though.