Have just tried the update on my other hackintosh, and it is exactly the same problem!
It freeze at exactly the same place/time in the update, when the update is about to finish.
Have tried just about all possible system definitions - all with the same miserable results.
There have not been any problems with previous updates, so have no idea what's going on this time.
I have also tried to uninstall the previous nvidia driver, and then install the new version, but the same thing happens every time. I'm completely lost...
Update: I finally managed to update to latest nvidia driver. The update was actually installed, although the computer was frozen. After the update froze, I restarted the computer and I booted to my backup partition, as I did several times to restore from backup
I repaired disk permissions from Disk Utility, and I could again boot from my Yosemite drive. And guess what, 343.02.02f02 was installed.
Have just done the same thing on my other hackintosh, and it was the same there was needed. Both are now running the latest nvidia updates.
But why this update has caused so many problems for me, I would still like to know.