I don't think we're going to see muuuuch in the way of modding on the XIII series. People have been ripping models out of it since it came out in order to make nude versions of everyone (ah, internet), but actually injecting modified content into the game code? I'm not optimistic for much. Square published stuff has never been particular mod-friendly, in fact the PC versions of FFVII and FFVIII are some of the better examples.

So yeah, I wouldn't expect many exciting mods. I have gone and pre-purchased XIII on Steam though seeing as there was a 10% offer on it. It's odd how utterly I can't be bothered to play it again on my PS3 but the thought of getting the PC version kind of excited me. And hey, the price is right, so no complaints here.