It looks like the latest update of the malware inspection rules for TMG 2010 blocks google.com, believing it is infected with JS/Blacole.BW.
It’s not as if many people use google… so we’ve got a couple a couple of calls about this so far…. and it looks like a few other people have run into it too.
So – the workaround
Open your TMG console
Navigate to firewall policy | Toolbox | network objects | Domain name sets
Edit “Sites Exempt from Malware Inspection”
add *.google.com
Done!