The world of SEO has always been a shifting, fluid medium. So it comes as no surprise that Google continues to refine its search algorithms, and in the process keeps us on our toes. But, with the release of Penguin and now Panda, I believe the core of solid SEO practices have not changed. Here is my number one piece of advice:

Write Content For Humans
Content is still king. The new Panda algorithm penalizes sites that have poor quality content. In the eyes of Google, poor quality content is unnaturally rich in keywords, and or is linked or copied from low quality sources. The solution: write original content for real people, and write it often.