I get wet and I enjoy it. I have a Nashbar waterproof pannier, I bought a pair for $35 I think, and it has proven to be reliably waterproof. I don't commute with a laptop but I've had an ebook reader and an Android tablet in there without worry, I'd put a laptop in it as well without worrying.

I have rain gear but it's more fun to get wet if the temps are > 60*F. I save the rain gear for colder temps.

EDIT: Fenders. I would enjoy riding in the rain a lot less without fenders, especially in the spring when the roadkill from all winter might be leaking and running downstream...