I just did a little more research on this.  According to the DNR, feral swine have been reported in 14 counties and have been sighted as far north as Canton.  Thus far, I dont think there is a large enough population to cause serious concern, but I agree-they should be dealt with before they do become a problem.  There are no specific regulations on feral hog hunting - the DNR is treating them as an invasive species, which means you dont need a hunting license to shoot them.  All you need is a FOID card, an appropriate firearm, and permission from the landowner.  Hopefully hogs dont become a problem here, too.