Alright, I did my due diligence... I upgraded everything I had, dumped old content, removed a few flaky things. we'll see if it keeps up. Please PM me if you see it hacked again. My guess is that it is a pretty low-level (read; EASY) hack the perp is doing. I find it odd that only the front page has been defaced... so either the hacker's too lazy to hack anything else, or their script is really crappy.
You know, the worst thing about "hackers" is that they're so boring. Most of them just find some site online with an exploit, and then go use it. There's no art to it, and they don't generate anything beautifully good, or beautifully destructive. Most of the script kiddies just do the online equivalent of squishing bugs, and then scream LOOK AT HOW GREAT I AM. It's so lame.