From his blog:
Perched on the windowsill of the NeighborGoods office, I recorded this awesome scene from the upcoming Transformers 3 movie. You can even hear Michael Bay yelling at people!
We also saw the Autobot “twins” zooming around. Apparently, one or both of them will transform and beat the crap out of this tiny little car. Totally awesome.
I think we can take this as confirmation that filming on Transformers 3 has officially begun and that Skids and Mudflap will appear in the movie (to no surprise but nice to know for sure).
Update: Ben Brown has posted two pictures from the Transformers 3 set on his Flickr page that seem to show off a plot point with a cross-out Autobot symbol and the phrase "Go Home". This seems to suggest that the public outing of the Transformers race and their war in the second movie is not going well for our heroes.
Update 2: Ben's coworker mickipedia also filmed the scene. The exact same thing with widescreen view and very slightly different angle. I believe that is Ben using his iPhone to film the above video.
Update 3: Bay denies the Twins return portion of this post.
Update 4: Bay says no, but these photos say yes to the Twins.