Check their guidelines before submitting. At DMOZ sites are manually added by human beings. If you think the editor has done mistake then you can report it to DMOZ.
Some times you may have submitted 10 years back and you might still have to wait ! It's not about the wait time. If you have a good quality website, you might get listed or else just move on. DMOZ is not god to judge who you are and how much quality your site is.
That has NOTHING to do with it... though, heh, if your site is sitting in the queue and an editor happens to check it out & gets a virus, you can be darned sure you will NEVER be listed, lol. But seriously, that is not a mandatory requirement. Samdar is right... submit & forget, your wait time (even for super fantastic sites) can be 10 years or more... and there is NOTHING you can do about it.
Yes submit and forget, or better yet don't submit and cut out the middle man. If you submitted check the topic you submitted to, likely no addtions there in years, which means there are no editors there. Why are there no editors? Being an editor at DMOZ is like being an Editor for the Encyclopedia Brittanica. No one reads it, no one uses it, no one buys it. Go get yourself some meaningful high PR links on Google and you will get better rankings on your website than a listing in this encyclopedia ever will. Now Jim is going to come back and say we get XXX editor submissions a week/month/year. Well you know, until everyone realizes that DMOZ has zero value people outside of the U.S. reading articles online from 2007 will still thing that DMOZ has some juice. They don't.