Hard for Sony to do anything at this point other than to release a PCI-Express based card adapter. The camera’s firmware could be updated for compatibility, and with a fast enough bus speed (the apparent bottleneck in using SD cards in EX cameras now) it could probably overcrank comparably.
If the JVC is accomplishing the 2x overcrank by means of a buffer internal to the camera, that’s also something Sony could engineer into their SD adapter. It would be worth some serious bucks to many EX owners, too.
Sony’s going to have to do some soul searching (for lack of a better term) to determine whether the $800 cards are going to push people elsewhere, or whether they want to get on board the SD ship before it’s sailed beyond their reach. They could charge for the high-speed adapters to current customers (including screwing us for a firmware upgrade we’d rather do ourselves, if required) and offer them with rebate to new camera customers.
That’s always the danger with proprietary formats. The stubborn stick to their guns and go the way of the dinosaur. Hopefully Sony will open up the EX line a little more rather than doing something foolish. If they win, we win.