I'm suffering of the same problem: generally during internet browsing with safari, but even with iphoto or other tools.
The screen freeze, I can move the mouse, but nothing else works.
So I've deleted flash, I've disabled GPU switch, and I hope to be able to work without problem till the next update.
But my crash reports show always the same header and in my case seems something related to Dropbox:
Process: garcon [4836]
Path: /Applications/Dropbox.app/Contents/PlugIns/garcon.appex/Contents/MacOS/garcon
Identifier: com.getdropbox.dropbox.garcon
Version: 1.3 (1)
Code Type: X86-64 (Native)
Parent Process: ??? [1]
Responsible: garcon [4836]
User ID: 501
Date/Time: 2014-10-31 03:25:06.170 +0100
OS Version: Mac OS X 10.10 (14A389)
Report Version: 11
Anonymous UUID: 1DF2FD73-94BE-B829-B9A0-E7236FE03208
Sleep/Wake UUID: 87420264-0A40-4B0B-AE75-76F3A6173970
Time Awake Since Boot: 120000 seconds
Time Since Wake: 28000 seconds
Crashed Thread: 3 Dispatch queue: service sync
Exception Type: EXC_CRASH (SIGABRT)
Exception Codes: 0x0000000000000000, 0x0000000000000000
Application Specific Information:
*** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'removing inactive plug-in <PKPersonality:0x61000014d7e0 com.getdropbox.dropbox.garcon(1.0) 40457D5E-1504-4B24-BD50-104566288697>'
terminating with uncaught exception of type NSException
abort() called
Application Specific Backtrace 1:
0 CoreFoundation 0x00007fff8c4ec64c __exceptionPreprocess + 172
1 libobjc.A.dylib 0x00007fff9164e6de objc_exception_throw + 43
2 CoreFoundation 0x00007fff8c4ec42a +[NSException raise:format:arguments:] + 106
I cannot understand why, but all my reports are consistent on this: