You *can* make containers using the scripting language. It's a teeny bit messy, but there's enough flexibility in the system to allow you to pretend. The only real limitation is the VERB NOUN match construct limitation, because that prevents PUT x INSIDE y or PUT a ONTO b, but it looks like those are being worked on at some point....
I think the way Quest handled containers is pretty cool. It has a reachability calculation which is quite sophisticated. :)