Remaning states which have neither gay marriage nor a constitutional amendent prohibiting it:
Hawaii
Wyoming
New Mexico
Minnesota
Illinois
Indiana
West Virginia
Pennsylvania
New Jersey
Of those, I'd say Illinois and Hawaii could happen by years end through legislative efforts. New Jersey and Minnesota will probably have something by 2016. Pennsylvania & New Mexico won't get anything as long as Martinez/Corbett are in charge. Indiana and West Virginia will probably get cracking on a constitutional ban pretty soon if the SCOTUS doesn't stop them first.
And Wyoming is a mystery.
