Joseph Gordon-Levitt’s site has a small mention/confirmation of Hesher.

But I’m just really excited and wanted you guys to know. Before starting work for Mr. Nolan, I’m doing this independent film called HESHER. I love it. Don’t wanna tell you too much about it, specifically, because personally, I prefer watching movies that I don’t yet know much about. I will say that the director is named Spencer Susser, and he’s the genuine article. Natalie Portman is producing and playing a part, and I think it goes without saying how cool that is.

Spencer Susser made a little Aussie horror-romance short film that garnered some attention, and is possibly why Joseph is so excited about working with him. You can view it here but be warned, there is quite a bit of swearing and violence.