It's not a full-blown IDE but given it's features set I think it fits into the IDE category. It gives you syntax checking and highlighting (you need an addon to do that in vim and perhaps emacs). You can run your code using a macro. It has autocompletion, code folding, project management, and plugin capable (so you can extend the built in functionality if you want).
As for the debugging stuff, most people that are just starting out with Perl don't use those features anyway. (And given enough tuits you can add that as a plugin, not that I'd want to do so.)
Update: Really the only things I see that keep it from being a full-blown IDE is debugging and interactive shells.