When is transporter 4 coming out?

Transformers: Dark of the Moon was suppose to be last movie that Michael Bay directed and it was and will be the last movie he would ever direct. Steven Spielberg said that he will probably direct Transformers 4 and or 5, if there is a next sequel.

Transformers 4 will probably be in stock and will start being filmed on September 29, 2012 and will be released during the summer of 2012. There has not been a confirmed of Transformers 5.

how is it going to come out during the summer of 2012 if they are going to start filming in september?