It's a completely feasible way of generating some more traffic. Even with a plain jane WP install set to multi-user and using default twenty-ten theme you can spit out blogs nice and fast.
Example of a bunch of simple installs (10-15 minute blogs) using WP3.0 and the default twenty ten theme. Although these are unique text and look pretty good, these I would consider just quick sites, feeders or splogs.
http://scarlettpain.fetishpink.com/
http://kylieworthy.fetishpink.com/
http://debidiamond.fetishpink.com/
I built about 30-40 of them as a test and most show up on first page for their long tail blog titles, like Scarlett Pain Porn Blog etc without any links or further development, pointing a few links to them will be easy as pie to start taking some more substantial terms with them.
Point of note, that is a fairly old, and un-abused domain I've used. And what I will do is update pornstar blogs on that domain as I add posts to my other sites, if I add a Scarlett Pain blowjob post on a site, I'll log in over there quick and also update the (gallery) and quickly do a re-write on the text to post it again. This makes updating the pornstar site into a no-brainer as I'm using my normal updates (not hunting content) and just using it in more places then one (but with fresh text).