A source close to the production of Transformers 4 has cleared up some elements about the film. While the term 're-imagining' was thrown around, the fourth film will be a straight up sequel to the last movie. It just won't be told through Witwicky's point of view. As to whose point of view it will be told through, that's unclear right now, but it's also unclear which - if any - human characters will be back.
The thing I was really curious about was how this 're-imagining' impacted the tone of the movie. The three films so far have been remarkably violent and dark for a series based on toys, and I wouldn't expect that to change. What I would expect to change is the humor - Bay seems intent on cutting down on the goofy, tone-deaf comedy bits that have seen some of our finer actors pissed on and tickled by giant robots.
"Michael realized it needs to be more like the last hour [of Dark of the Moon]," this source told me. So expect lots of big action, lots of carnage, lots of military badasses, very few silly bits.