To me, asking if you should submit to directories is like asking if you should post on forums or comment on blogs. Not all directories are the same. There are some well maintained directories, and many times over the years the submissions to these directories help rankings.
Interesting that the Link Acquisition Tool in labs here on Seomoz points a user of that tool to lots of directories.
One person that has maintained a wonderful directory list for almost 10 years now is Dan over at info.vilesilencer.com and great place to start if you want to include some smaller but well maintained directories in your SEO (and lists the larger ones too).
