You definately have to get status checks at the DMOZ forum because if its in the wrong category, they will most likely move it there and then. The system is far from perfect but if you utilize what little tools there are you increase your chances pretty signifigantly.
I have two sites that have been in the DMOZ queue since 2003. Every status request has been met with a useless "Its still waiting" response. Yeah... whatevah...
Problem is, DMOZ data is used on so many sites that actually getting listed is pretty valuable. Currently there are 302 sites listed in DMOZ as using their data; the actual total is probably much higher considering the plugins you can get for the various CMS.
I think it all depends on the category and the editor. If you are lucky and the editor for your category is responsive I think the wait time is not more then 2-3 months. For example I listed one of my sites in just one month.
That's usually the best way. It usually gets you a fast response. Not a helpful response, mind you. Just a fast one. usually insulting you and telling you not to ask again for another 6 years or they'll kidnap and torture your pet rabbit
Dear DMOZ - I submitted a site about 6 years ago and would like to request a status update on the... Hey! What's that horrible noise ?? OH NO!!! FLUFFY!!!!!!!!!!!!