Just out curiousity. I just finished shooting out an article about this very subject and wanted to post up some responses to see if my fellow marketers/website builders suffer from this egregious disease. Keyword paralysis, to me, is the incapability to focus on doing a set plan once you've found a certain set of keywords. Personally, i've broken free from the paralysis once i took my 20 or so long tail keywords, wrote webpages built around them, monetized them via adsense, and then let them bake for a month or two.
You know what finally broke me from this disease? Seeing the revenue

Once you see what works, this disease starts to fade..slowly, but it goes away.
What sort of things have you done to overcome it?
Are you still suffering from it?
I'm a web developer and iOS app developer - I'll make you a website or app! http://949web.com
specializing in SmartPhones , Internet security, high tech gadgets, search engines, tech shows, digital cameras.