It certainly won't hurt. When I search for some of my sites keywords, I see directories with my link in them. Rumor is google is trying to put a hurting on directory sites, but not sure how true or how successful they are. I'd say if you have the time then to submit, especially for new sites.
A lot of focus seems to be on the pagerank of directories rather than the traffic they provide. Can anyone please recommend some directories which provide traffic?
Dmoz is a must, but they have a huge backlog of submissions right now. I have submitted to over 100 directories (manually), and there aren't any that I get more than a couple of hits off of. It's very sporadic.
Aaron Nimmocks gave some great advice in this post: http://forums.digitalpoint.com/showpost.php?p=344488&postcount=3 Using the search terms he outlined for Yahoo with your own relevant keywords really helps narrow down those directories that you should give priority to. Go read it then give Aaron a big greenie. For one new site I was doing fine in MSN & Yahoo and just beginning to get some loving from Google before I tried Aaron's advice. There was no other traffic from anywhere. Now I have a steady trickle from relevant directories too plus the relevant IBLs which certainly won't hurt the site.