[The Dark09]

Confirmed information

* June 20th, 2009 — Michael Bay will be returning to directing duties.[2]

* June 30th, 2009 — Ramon Rodriguez will be returning as Leo Spitz in a larger role.[3]

* October 1st, 2009 — "Day One" of preproduction work. A story has apparently already been worked out. The day began with a meeting between Bay and Industrial Light & Magic which was followed by Bay and writer Ehren Kruger flying to Rhode Island to meet with Hasbro about new characters. Bay confirmed a proposed release date of July 1st, 2011.[4]

* October 6th, 2009 — Roberto Orci and Alex Kurtzman will not be returning to write the film. All writing duties were given to Ehren Kruger.[5]

* Michael Bay stated on the video played at the end of the Revenge of the Fallen Blu-ray AllSpark Experiment game that the third film will go deeper into the Transformers' history (cue lots of Unicron imagery from Transformers: The Ultimate Guide) and that it will have more screentime for Bumblebee. But it did say in the message that he'll say lies...

* January 5, 2010 — James Avery confirms he will be playing a new Autobot named Silverbolt. No word on if this is the same character as ROTF Silverbolt.[6]

* February 7, 2010 —Tony Todd says he'll be back in some capacity [7]

* March 2, 2010 — Optimus Prime and Bumblebee are going to get updated/revised designs that in Bumblebee's case reflects his maturation. [8]

* March 22, 2010 — Michael Bay announced that Frances McDormand, John Malkovich, and Ken Jeong had joined the cast, as well as the Ferrari 458 Italia would become the "newest Autobot." [9]

* April 7, 2010 - Variety reported that Kevin Dunn and Julie White will be returning as Sam Witwicky's parents.[10]

* April 27, 2010 - Tony Todd hinted at the Calgary Comic and Entertainment Expo 2010 that he would be playing a human character. [11]

* May 4, 2010 - Paramount Pictures confirmed that Patrick Dempsey has been cast in Transformers 3 to play Mikeala Banes' boss.[12]

* May 11, 2010 - Michael Bay claims: "The Twins are not back in T3."[13] If you believe that, we've got a space bridge for sale.

* May 19, 2010 - Megan Fox is suddenly dropped from the cast. A new love interest for the Sam character is slated to be casted.[14]

[The Dark09]

I got all of this from Transformers 3 - Transformers Wiki

[The Dark09]

Transformers 3 (actual title to follow) is scheduled to be released on July 1, 2011.