As The Verge just repoted, it has received a press invitation from Google for a "breakfast with Sundar Pichai", Google's head of Android and Chrome OS, which is held on July 24. Other then unveiling the when and where, Google seems to be pretty shy; not spilling any beans about what the event could possibly be about. It's clear that it is mobile OS related - but this can be everything - from Android to Chrome OS. Nevertheless, The Verge speculates that the event might be about Android 4.3, which is long overdue to be announced, but as The Verge also wrote, little is known about Google's upcoming Android revision; which could include everything - from support for Bluetooth Smart to the updated camera app.
In any case, the event will start at 9 AM Pacific Daylight Time (which is 18 o'clock CEST here in Europe) and the invitation even mentions a "livestream". So all of us, who weren't invited, should be able to follow the event in real time anyway.
Cheers ~ Arne