I got slammed by Penguin.. I got slammed by Panda... Here's what I can say for sure... Don't freak out right away.. Usually when these updates occur, things are in flux for several days, even a couple weeks. Then things start to settle out and you can see exactly where you stand.

Panda is about content. So if your site has "thin" content, you're going to end up being affected. In fact, if your site has thin content then you're not going to rank very well anyway.

You want really good content on your site.. Every blog post should be probably 500 words or more.. Your site should have real value. Visit your site and ask yourself.. Would I visit this site to get the information I want? Would I come back to this site for more information later? If you are painfully honest with yourself and answer no, then it's time to redo it and make it a site you would use yourself.