Hyperbola has heard that following the rocket motor tests that Virgin Galactic publicised with videos earlier this year (and its prime contractor Scaled Composites reported on its online test logs) work is focusing on the flight weight engine
In all rocket engine projects intending to fly something there are engineering development units that are used so the design can be tested while components may be at an earlier level of maturity, earlier than they have to be come the final flying version
But eventually the development work has to approach the mass and performance engine targets required of the propelled vehicle
Hyperbola understands that testing and firings are ongoing and that while the Scaled test logs web page has not been updated since 20 May more videos and test logs can be expected later this year, in a few months time
Around the time the prototype SpaceShip Two will be rolled out for its unveiling and first captive carry flight on its mothership WhiteKnight Two Eve perhaps?