Works for me on GNU/Linux.
Is 24.3.92 hanging at the exact same time that 24.3 works?
Ie, are you sure it is not an issue with the remote host?
Yes, it always hangs on recent builds while the previous builds always works. I can swap between the versions to reproduce the problem, so I don't think it's a host issue. Also, it appears to not only apply to melpa, but to all three repositories. It appears to mostly work for the first two (elpa and orgmode). I.e. it always hangs on the recent builds, but usually at the third repo - melpa.
It works fine on e.g. 2014-04-01, 2014-05-01, 2014-05-17 and 2014-05-24.
There is no build dated 2014-05-25.
It fails on 2014-05-26, 2014-05-27, 2014-06-01 and all the more recent ones I've tried up to and including 2014-06-28. [*]
So it looks like something may have changed on 2014-05-25 or 2014-05-26 that affects me.
It also looks like there weren't any changes to the build scripts for emacsforosx between April 9 and June 14, so I'm thinking that the problem isn't in the packaging.
[*] The two most recent builds from 2014-06-29 and 2014-06-30 hangs owon't start at all and hangs at a local script. I suspect this is a different problem.