The co-founder and CEO of Siri has left Apple according to All Things D. It’s being reported that Dag Kittlaus’s exit was planned for a while, and that amongst the reasons, Kittlaus was looking forward to returning to his family back in Chicago:

[quote]There were several reasons for the departure, which was amicable and has been planned for a while, sources said. They included Kittlaus’ family being in Chicago, a desire to take time off and an interest in brainstorming new entrepreneurial ideas.[/quote]

The report has also indicated that key members from the Siri team still remain at Apple and are assisting the company with the new Siri integration in the iPhone 4S.