I realize this thread is a little bit old, so maybe I shouldn't be bringing it back, but there is some new info.

The Overlord DLC just dropped today. It features the Hammerhead tank from Firewalker, and a good deal of geth to kill, but the writing seems sparse. A lot of action, but not as much dialogue as the main story missions. My companions haven't spoken the whole mission.

There is a good Portal reference though, so it gets props for that.