LEGO and Rubik's Cube go together like peanut butter and chocolate. The creativity of LEGO goes hand-in-hand with the logic and problem-solving of Rubik, and both are chunky, brightly-coloured 'toys' which appeal to both males and females alike.
The idea of creating your own cube which is customiseable and yet still solveable is exceedingly appealing to fans of both products.
The above is an extremely crude design as full functionality would require some liaison between the Rubik and LEGO corporations to achieve proper internal mechanism mobility.
It should be noted that customized LEGO Rubik cubes already exist (most notably by Kenneth Brandon (http://www.youtube.com/watch?v=4iiGc5Rt3Gc&feature=plcp&context=C33d0bffUDOEgsToPDskKGNQXaHwSnuLDZ-7Inv4SI)) but to have something officially licensed which did not require superglue to achieve has incredible appeal.
Ideas, comments, thoughts, suggestions, queries are very welcome indeed!