There have been many people asking questions about the future of Wine Staging, turns out it's no longer going to have any new releases.
I won't quote the entire post titled "Future of Wine Staging", but the gist of it is that they just don't have the spare time to put into it now. They have full time jobs, so naturally that doesn't leave much for something like this. I fully understand their situation and wish them all the best, I've seen so many people appreciate the work they did to bring so many different patches together for testing.
The good news, is that there's already a fork available. On top of that, Wine developer Alexandre Julliard posted on the Wine mailing list about keeping it going in some form, so there might be light at the end of the tunnel.
Will be interesting seeing what happens, from what I understand there's a number of games which only work in Wine Staging due to a fair amount of patches not being in Wine proper.