Update 1: Added the sweet animated gif from io9.com.
Update 2: The transformers_movie Instagram account (link below) has posted screenshots with labels for some of the characters. Its a fan run account so still nothing official. From those labels, the guy in beginning of trailer below giant ship is Lockdown. He is also the guy that had head transform into a gun and is holding Optimus upside down. The two headed thing is identified as Strafe (aka Swoop), and parachuting Autobot is Crosshairs. Again none of this is official, just speculation. The gray, Megatron looking robot is probably the alt mode of the gray Freightliner truck. Thanks to Feris O. for the heads-up.
Update 3: Hi-res screencaps at the TFW2005 link below for those that really want to dissect the trailer. Also updated the blog title banner. Thanks to Jeffrey Marshall of Pixel Rally who has been updating those banner over the years. The new one makes use of the Age of Extinction font style from the trailer.
Update 4: Added link below for a 1080p dowload of the teaser, courtesy of MichaelBay.com's Twitter account.
Trailer Links YouTube | MichaelBay.com | 1080p Download | Various Languages | AdBlitz | NFL
Screencaps: TFW2005 (Hi-Res) | Instagram | Seibertron