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There are a number of different ways in GA, Omniture, etc to track specific link clicks from places like the footer...many of which I'm not extremely well versed in, but the googles certainly know. I would definitely recommend doing that to get a pure numbers look at the situation.

I'd also though recommend you modify Will Critchlow's mturk method of grading content for a look at usability of the footer and/or use something like usertesting.com to get some qualitative feedback on the footer. Guaranteed you will get a look at your design that you've never even thought of, and the cost is so extremely low when you consider what you can get out of it.

replicate-googles-panda-questionnaire-whiteboard-friday

Finally a PRO question, I can answer

My org only does marketing for nonprofits and uses this a ton. The impact can be big, but it won't last long, so it's best to start with a bang around a major event, a holiday, etc and then not belabor it for too long.

I can't recall if they have this case study on their site or if you need to have them send it, but check out their World Cup case study. It's for profit of course, but it's kind of cool how twibbon was used to grow their audience.

I second Alex's & EGOL's recommendations and will add this. It looks like you're in Seattle. It'd probably help to contact some local SEOs and see whom they might recommend if they're not a fit. Ross Hudgens, Click2rank, Ian Lurie, and Distilled all come to mind. They all post a lot of content on SEO, so you can research them that way and have all spoken at some of the bigger, more respectable SEO events/conferences. I'm sure there are plenty more that I'm not thinking of in that area that are good as well, but I'd start there.