Rob Coppinger links to a presentation by Rick Newlands on his "Black Cab" winged reusable nanosat launch vehicle design, which would be carried to launch altitude by White Knight Two:

• PICTURE: Black Cab - a reusable flyback first stage -- Hyperbola

Coppinger reports that Newlands "has since been contracted to undertake an analysis of expendable and reusable options for LauncherOne".

As another UK space activist mentioned to me recently, if it's a UK commercial cargo vehicle, it should really be called White Van rather than Black Cab... ;-)