The test program for WhiteKnight2, the VMS Eve, is escalating with approximately 2 test flights per week.  Here are the key achievements:

Flown to 45,000ft
Flown 6.1 hours in a single flight
Pulling g’s at altitude up to 2.5g’s
Practiced putting the wheels up and down at various altitudes and speeds
Practiced a stall – meaning they shut down the engines and re-start them inflight.
Flown to a peak speed of 340 KTAS with the landing gear both up and down. This is approximately 630kph/390mph
For those interested KTAS stands for Knots True Air Speed and measures the speed of an aircraft relative to undisturbed air. You can find out more about this on Wikipedia.