I think they would have to explicitly do a version for the 3200 firmware (it isn't necessarily the same as the 3100) but I think in principle it would be possible.
It seems that they work on the cameras they physically have (3100,5100,7000,800?) and each camera requires a new hack (although some share parts of the firmware which makes certain models easier to get started with). If they have the physical camera to work with, the time to do it, enough people to test (who are willing to risk potentially bricking) then all models are possible. It is pretty cool stuff but very time consuming by the looks of it!