Don't know if this has already been mentioned, but saw this over on FlyerTalk. From 19:00 to midnight on July 26th, because of the Olympics...
"All Airspace will be closed for 150km around Paris between 19.00 and 00.00. Roissy (CDG) and Orly (ORY) will be closed for that period of time."
If you happen to have had a flight scheduled into Paris for those 5 hours, I'm sorry.