So is it safe to assume that we can use the 2G cases for the Sept 2009 touches?
They should. For the most part any iPod accessories will work with any iPod/iPhone as long as it has the correct connector (i.e. isn't a shuffle) and physically fits if there's a dock.I assume all the electronic accessories for the 2G will work as well?
Yes. They are identical in shape. Using a 2G case with mine.