Well this wasn’t a totally unexpected occurrence really, but yes the Alpha client was leaked and people have started to study it. No I will not link to a download in this blog or to a site that has it.
A couple of things that are perhaps interesting to note are that the client seems to use the same censor list as PSU. Which means, at least in the alpha, you are prevented from saying such nefarious terms such as “shieeeet”, “nakedbabes”, “jew” and “sd”.
The other thing is the client appears to be able to patch itself through the launcher, which as any players of previous online games of the franchise will know is new. In both PSOBB and PSU you could only patch in-game after the login screen (but before it verified your details, at least in PSU’s case). Yes, Schthack PSOBB does have a patching mechanism in its launcher too but that’s something Schthack made themselves.
It also seems to include PHYSx (physxcudart_20.dll). What the game actually uses it for is as of yet unknown, however.
There may be more details unearthed from examining the client, but remember this is an alpha so the chances are good that things will change.