I am experiencing the same thing with my Beefsteak, but not quite as severe. I noticed it starting about a week ago. I have a small cherry variety growing about 6 feet from the Beefsteak and it is not affected. Yes, we've had a lot of rain where we live, and that is what I'm suspecting (and hoping) is what's happening. My first thought was that a mole had tunneled under the plant. Tomorrow morning I will take a picture and post it. I am also anxious to hear from others to see if this is something serious or not, so I will be following this post.

Here is a picture of my plant suffering from the leaf curl.

...and a closeup