Best Penguin Solution = Take a deep breath, check your Google Webmaster inbox, and keep an eye on your rankings for a few more weeks.
If you're still indexed and you didn't get a warning notice, you're probably fine. Your traffic changes may have more to do with the fact that your site isa niche site in an industry that is susceptible to macroeconomic forces.
My site is the same way. I'm targeting potential consumer bankruptcy filers in the Seattle area. My analytics data swings form week to week. If you've been tracking with analytics for at least a year, then your best metric is year over year traffic comparison, i.e. April 2011 vs. April 2012, or a specific week in April 2011 vs April 2012.
If your traffic is steadily declining and business cycles or year over year comparisons don't explain it, then you should consider link building and link removal strategies.
Penguin freaked a lot of people out, myself included, because they had lots of directory backlinks from back in the day that are still hanging around. I have about 600. Two of my biggest competitors have 3,000+. My biggest competitor has 10,000+ links from random directories, they do reciprocal linking, and they still outrank my on two of the biggest keywords in our industry.
Based on my analytics tracking, my numbers haven't changed; and based on my competitive analysis, my competitors haven't lost position. If you take a look at the April 24 announcement from Google you'll see that Penguin affects a relatively small percentage of queries - 3.1% - as opposed to Panda which affected about 12%. 3.1% of all English language web queries is not that much, considering Google's search volume.
In my opinion, Penguin is a huge warning shot. If you were one of the worst offenders you got hit hard or you got a warning notice. But for the rest of us, we're officially on notice about artificial link building and web spam. My guess is that in the next few algo changes Google is going to take an unfriendly look at webmasters that continue grey hat/black hat link building after Penguin.