Engadget is reporting today that Microsoft has begun sending out invitations to a October 11th press conference for 2 PM in London. Microsoft neglected to say what the press conference would be about, but rumors over the past weekend lead us to believe it will be the official announcement of Windows Phone 7, along with a release date and several device announcements.

Microsoft has already released the RTM (Release to Manufacturing) build of Windows Phone 7, further hinting that the newest mobile OS from the software giant is nearly complete.

We'll be covering the press conference all day on October 11th.