Merrick here...

Seems TRANSFORMERS 2 will shoot a sequence or two at the Bethlehem Steel facility in Pennsylvania. The spread will stand-in for "a fictional Chinese city populated by people from the Lehigh Valley."

The movie crew will film in Bethlehem during the first week of June and will use the blast furnaces as the scene's backdrop, Callahan said. ''It's going to bring a tremendous amount of excitement to the city,'' especially for any locals who nab walk-on roles, he added.

According to an announcement from Heery Casting of Philadelphia, the filmmakers hope to cast local ''Asian men and women, boys and girls, ages 7 [to] 65'' as paid extras in the movie. In particular, the crew hopes to recruit extras of Asian descent who have military backgrounds.

...says THIS ARTICLE at The Morning Call.

The story also features a picture of the location...should look pretty amazing on screen.

Also, the folks over at IGN interviewed co-scripter Roberto Orci about the project. Orci says that Soundwave (and possibly Ravage) will appear in the film, about which he said this:

I think the second one will deliver on a true Transformers story. You know, the first one, we had a limited budget for what it was. Every second of Transformer time is a million dollars or whatever the heck it is, so this time, because we were able to prove through the whole thing that it's a viable live-action movie, we have a little more freedom this time to actually learn about the Transformers, see them, hear them. It's a better balance between the humans and the Transformers.

This from the IGN article you can find HERE. There are a few more interesting details; check it out.

The project starts filming in three weeks.