More information has been released about the new Elecraft internal two metre transverter that will be shown at Dayton. Elecraft has just posted a PDF data sheet for the K144XV module. The product won't actually be available for a few months, though.
It looks a pretty small board, but it will probably cost more than you would imagine from the picture, as you get a new fan panel with a BNC jack for the 2m antenna, and a replacement KXV3 module is needed to provide the IF output. Probably you need a new side panel as well, since that is what it is attached to. But they've managed to fit it in along with the KXV sub-receiver module.
It's a neat option, but personally I'd have been more interested in a new range of Elecraft's existing transverters, styled to match the K3 (rather than being in K2 gray/green) and with better heat sinking to withstand continuous duty modes like FM. Perhaps next year.