Anyone know?

With an adapter.

I heard that the 370/371 can but not the 300/301 but a firmware update may be all that is required to all older cameras.

A firmware update to use the micro P2 cards is required on all P2 cameras, except the new PX5000 and the new Varicam. The 300 and 370 are very similar, I was hoping an update would work on both. Panasonic's website says the "HPX370 series" can be updated. Is the 300 included in the "series?"

It seems only AVC-Intra capable cameras can be updated, and not all of those are eligible. The Varicam 2700 and 3700 cannot be updated for micro P2.

I just got the official word from Panasonic: NO micro P2 upgrade for the HPX300.

I just got the official word from Panasonic: NO micro P2 upgrade for the HPX300.

How odd. I was under the impression that all cameras with AVC-Intra would be able to use micro P2 with the adapter.