More than a few people are like me and took the dive into Windows 8. After two days of constant BSODs, I figured every thing out. Windows 8 itself is extremely stable. The only thing that crashed was Minecraft, so please don't assume Win8 is garbage. It's just new.
To fix crashing you may need to do all or some of the following. (Depends on your hardware, of course.)
1.) Update your video drivers to Windows 8 drivers provided by the manufacturer.
2.) Download and install Java 32bit for Windows 8. (you can install 64-bit too, but I will explain this later)
2.) Add an exclusion to Minecraft.exe for Windows Defender. Instructions here: http://imgur.com/41uJ8
3.) Once you open and update the game, go into the Options and change "Render Distance" to "Normal."
This solved all performance issues. The exclusion for Windows Defender prevents the virus scanner from scanning the game while it's running. You guys know Minecraft generates data as it runs and this only slows down the game. (and can cause a crash) Java 64-bit does not work properly. It will BSOD the machine if you set Render Distance to Far. (Far requires 64-bit, if you did not know) I tested this repeatedly. I would run the client on Normal. Play for a bit and then just switch to "Far." Instant BSOD, every time.
The first two steps are no brainers. If you can run the game after drivers / Java updates, good for you. Some others will require additional steps. If this does not work for every one, we will more than likely need to build on the topic.
Tested and working successfully on Windows 8 Pro 64-bit. GPU is a HD 6950 2GB.