Made in China, 2010 - 2013.
(8x8x8: plastic, 3+1/4", red opposite orange, yellow opposite white, blue opposite green,
9x9x9: plastic, 3+3/4", yellow opposite gray, orange opposite red, blue opposite green,
10x10x10: plastic, 3+7/8", yellow opposite white, red opposite orange, green opposite blue,
11x11x11: plastic, 4+1/2", yellow opposite black, orange opposite red, blue opposite green)

The patent for the Rubik 6x6x6 and Rubik 7x7x7 cubes presented designs for up to 11x11x11 cubes. Subsequently 8x8x8 through 11x11x11 cubes were mass produced in China. The even dimension 8x8x8 and 10x10x10 cubes shown on top above are square in shape but with larger edge and corner tiles, and the odd dimension 9x9x9 and 11x11x11 cubes shown on the bottom above are also slightly curved in shape.

The reduction to a Rubik 3x3x3 solution used for Rubik 4x4x4 and Rubik 5x5x5 solutions can be used for solving these larger cubes.

Further Reading
Chris Hardwick's Page On Big Cube Speed Cubing, from:

http://www.speedcubing.com/chris/bigcubes-info.html