After a discussion with my colleague Michael Willers (his famous security blog is down moving and will be up again soon...) I'd like to push it further/see it from a different point of view: (Especially in the web) Applications are content or at least provide content (That is the was HTTP, REST, etc. work).
I think also Jacob Nielson would agree that forcing the user to use a path instead of allowing the user to decide is wrong.
Keep that in mind when you think of using page flow/task concepts in your applications.
P.S.: I got to admit that I like some of the IKEA furniture :-)