Taken from the games official site:
-Fixed bug that would cause the menu to not show for 5-10 minutes at startup while authorizing with steam; also fixes bug that would say a player doesn’t own a copy of the game and locks them out, when they do own it.
-Fixed bug where players would get a blank screen when clicking start after manually typing in an IP/Port.
-Fixed memory management on dedicated servers: now if players disconnect their memory is freed and not cached any more.
-Known Issues: Some player hosted games still have incompatible NAT routers preventing other players from joining. A quick solution is try and let your friend host instead

I guess the useful part is the memory management for servers.

where is the multiplayer fix? The old .reg way to change names doesn't work, the game changes it back to -=[SoftBp]=-

I have a problem when trying to play the game.. I've extracted it and ran the game like instructed, but when it boots up it says that my steam client is not running or no connection available.. I dont understand what could've happened. The thing that confuses me is that i tried it on my other computer, and it worked. the only difference is between the both of them is that the one that didnt work is windows 8, and the one that did is windows 7. If anybody has had the same problem, or just knows how to fix it please let me know.

P.S: I have already tried to reinstall my C++, and my steam is running. But still not working as it should. This is also a new computer that its not working on, so i imagine it might be software that im missing? If i am correct please let me know.

@lemonhead21, I have the same problem. Only have Win 8 and haven't tried it on anything else.