In case you haven't read, there has been a speculation of this by our fellow. But it has been further confirmed, as it is written in Inside Movies...
Here is one small step toward understanding Transformers: Dark of the Moon, and one giant leap forward for toy-collecting fans.
Hasbro’s new line of awesome playthings reveal tantalizing clues about the third installment in the shapeshifting alien robot saga. We’d say “meet Sentinel Prime”, but loyal Transformers geeks have already encountered him in December’s teaser trailer for the movie — they just didn’t know it.
Lookee-loos on the Chicago set of the movie long ago heard mention of Sentinel Prime, most often associated with a boxy firetruck used in the battle scenes. But until now no one has seen the face of the character (which kinda looks like F. Murray Abraham) to make the connection with the mystery ‘bot featured in the trailer. The official name of the toy is “Mechtech Leader Sentinel Prime.”
And more from
MTV, here's what Michael Bay said regarding the character:
On the carpet, Bay also briefly touched on two new alien bots set to debut in "Dark of the Moon." "Sentinel Prime is great. He's great," he said. "I can't tell you anything else, other than he's great."
The site further explained about the new toys in the toyline, The Ark, revealing it to be a playset:
Hasbro also exclusively revealed to EW a new kids’ playset designed to be a Transformer-carrying spacecraft — the Ark — which fans of the original ’80s series will recall as a big, yellow, half-moon-shaped cruiser that was crashed halfway into the side of a volcano. (Think of a massive, metallic, robot-stuffed pita). In the cartoon, it served as the Autobot headquarters, but in Dark of the Moon that smashed hulk that serves as Sentinel Prime’s living tomb is the updated version of The Ark.
The site also managed to dig a bit about Megatron from Bay himself:
When I visited the set of this movie last summer, Bay said Megatron would start the movie in Heart of Darkness mode, hiding in the jungles of Africa, nursing his wounds, and vainly hiding his pulverized visage while plotting — what else — revenge.
Bay also confirmed then that one new villain in the picture would be the fearsome cyclops Shockwave, another blast from the ’80s toyline that started it all. Meanwhile, the recent Super Bowl ad for the film also stirred speculation about what new metallic characters would be joining the cast. Laserbeak, anyone?
Hiding in the jungles of Africa...now the fact that Megs will be a truck in such appearance makes sense to me.
Transformers: Dark of the Moon will hit the theaters in July 1, 2011!