There seems to be a lot of people experiencing a problem after upgrading to WordPress 3.5
If you get the following error (or very similar)
Parse error: syntax error, unexpected T_VARIABLE in wpincludes /functions.php on line 192
Then it is believed your wordpress upgrade has been hacked.
This has now been confirmed as a definite hack. To confirm, YOUR WEBSITE HAS BEEN HACKED!
You can review this forum for help on fixing this error
Some people are simply replacing the functions.php file with a new copy of this file, however there is likely to be a number of files in your root directory (take a look for files that just start with a load of numbers)
It is recommend (strongly recommended) to fix this error permanently and to remove the hackers files from your website that you work through the following resources. (I can help if required but i do charge $100 for this as its a lot of work)
You need to start working your way through these resources:
Unless you do all these, the hacker will just walk straight back in again and reinfect your website.
Ill update this post when a patch from wordpress is released or further advice is received.