Transformers 3 production continues at Wacker Drive in Chicago and based on recent images it is a scene that mostly involves Patrick Demsey, Shia LaBeouf and probably a Transformer or two. Below is a sample of photos from a 56 photo set from the location as the two actors climb and lay down among the debris while Bay does his thing. Not sure what is being filmed but seems like a hero moment for Dempsey's character. The set was taken by a Transfan that managed to sneak onto the set. The full set can be found at The Chive. Thanks to Mackie for the link.
It also seems that a new Transformer may have entered the scene with a red Jeep spotted in beautiful condition (vs. the damage of the rest of the non-TF vehicles being used). The video (below) from MGRead, shows it on the back of a production truck so nothing definitive, just something to keep an eye out for. Two other videos show more filming from the last few weeks, behind the scenes stuff and Josh P provides more footage with a little CGI insertion of 'Bee for fun.
More set photos: PopSugar | Shia and Patrick | Josh, Shia, Tyrese