Ok, I finally figured it out, and thought I might as well share my findings with anyone else who has been as frustrated as I was with this problem.
I had installed the beta client on both my laptop and my old stationary computer, and after failing multiple times on my laptop to make it work after updating to patch 9, I thought I'd check if the same problem occured on my other computer. It didn't. It worked fine.
So, I thought this may be because I didn't download the client I've got installed on my stationary computer from battle.net, I downloaded it from a torrent I found using google (from before I got my beta key).
I then uninstalled SC2 beta, found the torrent and downloaded the US client (slightly older version, from february or so), and installed it. Took a while to update it, but once update finished, I launched it, and it didn't crash.
Another thing to note is the loading bar is different from the version that does crash. The enGB client I downloaded from account management on battle.net was striped, while the enUS client I downloaded via a torrent had a solid colored loading bar.
Anyhoo, due to some patch problems, I got nowhere with logging in via the client when using the regular launcher, but as with many others, launching via the SC2Switcher.exe in the SC2 beta\support\ folder worked, and I now get the correct message when trying to log on to my battle.net account via the SC2 beta launcher, which is that battle.net is currently down, undergoing maintenance.
So now I've just got to wait until Blizz fixes the servers, and I'm good to go.
TL;DR - enGB client downloaded from battle.net account management page is broken and causes the game to crash when launching it, after finished loading. Use the enUS client and it should work.
Hope this helped.
I had installed the beta client on both my laptop and my old stationary computer, and after failing multiple times on my laptop to make it work after updating to patch 9, I thought I'd check if the same problem occured on my other computer. It didn't. It worked fine.
So, I thought this may be because I didn't download the client I've got installed on my stationary computer from battle.net, I downloaded it from a torrent I found using google (from before I got my beta key).
I then uninstalled SC2 beta, found the torrent and downloaded the US client (slightly older version, from february or so), and installed it. Took a while to update it, but once update finished, I launched it, and it didn't crash.
Another thing to note is the loading bar is different from the version that does crash. The enGB client I downloaded from account management on battle.net was striped, while the enUS client I downloaded via a torrent had a solid colored loading bar.
Anyhoo, due to some patch problems, I got nowhere with logging in via the client when using the regular launcher, but as with many others, launching via the SC2Switcher.exe in the SC2 beta\support\ folder worked, and I now get the correct message when trying to log on to my battle.net account via the SC2 beta launcher, which is that battle.net is currently down, undergoing maintenance.
So now I've just got to wait until Blizz fixes the servers, and I'm good to go.
TL;DR - enGB client downloaded from battle.net account management page is broken and causes the game to crash when launching it, after finished loading. Use the enUS client and it should work.
Hope this helped.