First, you need to be approximately 5' 10". Second, it's best if you understand that this is a non-singing, non-speaking, non-dancing volunteer role. Third, supers are governed by fairly strict rules.
You will be on stage in full makeup and costume, in front of thousands of people at each performance. That sounds like fun to me, but might not be for you.
So, we know that there's a concept of some kind that will involve multiple Werthers on stage. I've seen a few productions recently with a similar, ah, feature: Willy Decker's Die tote Stadt and Achim Freyer's Gotterdaemmerung. Whether Werther will benefit from this kind of treatment, well, we'll see.
For the rest of this posting, I quote directly from the press release.