FTP may be a bit more difficult than other things, since
AFAIK the Pre doesn't have any built-in classes for doing that. The Facebook and Photobucket uploaders both use the Pre's built-in web services frameworks to upload.
That's not to say that it's not possible, just that it won't be as easy as adding support for something like TwitPic that's based on a web service.
I'm not making any promises, but I might start looking into this soon. It's mostly contingent on whether or not I'm satisfied with my work on upgrading the text autoreplacement file, but I think there won't be much more to do on that.