It isn't necessary at all, no; you could easily setup Contact Form 7 to handle submissions and integrate any number of popular membership suites to handle posting. Have a dig around CodeCanyon.net, though. I seem to remember they have directory plugins. The above membership idea might even be a better option, though, depending on what membership functionality those directory plugins offer.

- Tom

In that case, I would avoid the directory software, which may not be as functional as a decent membership suite, or even something custom. You can easily develop your blog for personal use now (perhaps with guest blogs and/ or outsourced content) and later on integrate a directory process. If you look at a setup like Cracked.com, you'll see a very successful website that, in essence, is a viral magazine, but integrated into the mix you have software to handle submitted content. And that brings up a useful final point: the directory model, after being hit by Google, is a weaker option than what you've see in operation at Cracked. User-submitted content is a powerful model, when harnessed correctly.

- Tom

If you don't accept submissions, then is it really an article directory ... or just a blog with all your own submissions?

I'm not sure what you are really trying to accomplish.

To me, if you want a true article directory, you need to set up your site to be an Article Directory. There are lots of plug-ins and software that will do this - some free, the better ones will cost a few dollars (but are still reasonable).

You can always move blog posts to an article directory later if that's what you decide you want down the road.

I say, decide on one or the other and set up your site to handle whatever you decide.

Steve

If I'm not mistaken, the Pligg open-source directory software is still available and free to use.

There are tens of thousands of junk directories still floating around out there, but that's not the fault of the software. Those "directories" are mostly made for junk links from garbage spun articles.

With a little work and TLC, the software might work for you.

As for the plan to "throw a multitude of different niches with different articles on it", you might have a hard time unless you have a way to lure visitors that doesn't involve search engines.

If I were to tackle something like this, I'd use separate sites to make tightly themed niche portals with carefully chosen articles, link lists, and user-generated content.

If you're set on Wordpress, set it up for multisite use and make each niche vertical on a separate subdomain or subdirectory.

Much easier to monetize if the site is tightly focused.