The FY-90 Controller is purpose built for Quadcopter use.

The Attitude flight stabilization system (AFSS), which is the heart of the FY-90Q, is an integrated 3-axis gyroscope and 3-axis accelerometer. AFSS forms a comprehensive inertial based navigation platform that calculates 3D flight attitude using proprietary FeiYu Tech algorithms.

When in full balance mode, the AFSS detects any changes to the models horizontal attitude. If an attitude change is detected, the unit will send out controlling signals to change the rotational speed of the Quadcopters motors to maintain stability.

The FY-90Q system features 2 flight modes.

Mode 1: Full Balance mode, in this mode the Quadcopters flight is fully stabilized on all 3 axis, resulting in extremely leveled flight. Suitable for Aerial photography, video, FPV and beginner Quadcopter Pilots.

Mode 2: Aerobatics mode, in this mode the control signals to each motor are very responsive. This mode is specifically for skilled Quadcopter pilots who want fast forward flight etc.

Specs.
Input Voltage: 4v~6v DC
Current Draw: 52mA (5v)
Size: 55 x 33 20mm
Weight: 20g
Max rate of rotation: <500deg / S

This flight stabilisation is much more sophisticated than the KK multcopter board that Hobbyking just sold, but it seems they are getting serious about the quad market and this is a good step in the right direction.

Price is US$ 109.00 and probably lower if you are a Hobbyking member. See the Hobbyking product page for more information.