Could be easily made up, could be genuine, guess we'll have to wait till the third to find out 'officially'
Worldofwar.net released a "leaked" schedule of the Blizzcon. The only interesting thing is the "Opening ceremony" which has 90% chances to be the announcement of the expansion.
No further informations, doesn't really look like an uber internal leak but I guess it's better than nothing.
Source: MMO Champion