I'm going to the games.  Am I worried.  Not very.  The new greek government has brought in security experts from Israel, the USA, and NATO is also in a support role.  The greek government is spending over 1 Billion dollars on security.
Having said that, I put in for opening ceremonies and didn't get them, and that's ok.  If anything were to happen, that would probably be the event.  I do have tickets to Men's Track and Field finals and Women's Gymnastics finals.  I will only have to walk 5 minutes up the street to catch the Marathon runners.
I'm psyched!