I too was unable to open the iCloud System Preferences after upgrading from 10.7.1 to 10.7.2.
Looking through the Crash Report, I noticed the following:-
Error Domain=NSCocoaErrorDomain Code=4 "The file âMailâ doesnât exist."
Now on my Mac the Mail folder is stored within an encrypted sparse bundle, with a symbolic link from the Mai from User/Library/Mail. This has worked fine on Snow Leopard and Lion. When the sparse bundle is attached I can use Mail, otherwise the system doesn't complain. But with 10.7.2 System Preferences for iCloud now crashes.
So the simple solution in my case was simply to make the Mail files available again, by opening the sparse bundle on which they are contained. Then iCloud System Preferences works again.
For anyone interested, here are the 1st few lines of the traceback:-
*** First throw call stack:
(
0 CoreFoundation 0x00007fff85998286 __exceptionPreprocess + 198
1 libobjc.A.dylib 0x00007fff847c7d5e objc_exception_throw + 43
2 Message 0x00007fff83efe012 __-[MFAccountStorage _accountsPlistPath]_block_invoke_1 + 412
3 libdispatch.dylib 0x00007fff86e0f224 dispatch_once_f + 53
4 Message 0x00007fff83efde6d -[MFAccountStorage _accountsPlistPath] + 33
5 Message 0x00007fff83efddac -[MFAccountStorage objectForKey:] + 140
6 Message 0x00007fff83efdcdf -[MFAccountStorage arrayForKey:] + 20