Nice writeup.  I think the Directory submission is transforming before our eyes, and soon the way we all do our link building will be more personalized and connected.  Thanks,

I would hesistate to even call it "limited." Directory submissions definitely have their place, especially if you are going after local search results.

Directories are, at best, good for strict white hat interaction. Any grey hat, blue hat, or black hat techniques will show results much quicker. I'm unsure of the long term worth, but yahoo directory aside, it can often take months for google to even recognize you've added them to a directory.

Good write up, most are just seem to be collection sites. Probably thousands of useless directories out there currently.