First of all, some terminology of the cube that you need to know. A "cubie" refers to any one of the small sub-cubes that makes up the entire cube. A center is a cubie that has only one visible face. it's color or number determines what that side will be, because a center cannot be moved to another side. Edges have 2 visible faces, and are positioned betwixt the centers. Corners have 3 visible faces, and each touches 3 of the edges.
A standard 2x2(x2) Rubik's Cube is essentially a 3x3(x3) cube, but lacking the centers and edge pieces. This presents a problem for creating a magnetic 2x2 cube in the same manner as in my dice cube and gfixler's magnetic cube. In a 3x3 cube, the corners always touch edges. Therefore it was possible to use identical polarities for all internal sides of the corners, as long as all the edges had opposite polarities. In the 2x2 cube, corners touch directly to other corners. No matter what system of polarities you used, there would be some situations that would make the cube unstable or explode.
So I scrapped the idea, until I realized that I could embed a steel ball inside the cube, to which each cubie would attach via a single magnet. The ball would not be a magnet, but rather just a steel ball or ball bearing. Half of the cubies' magnets have one polarity, and the other half the opposite, so that no matter how the magnets are arranged, they will always be relatively stable.
This cube feels very similar to a real cube, albeit quite a bit heavier. The cubies do not snap into position after being turned, as in the 3x3 magnetic cube, since their attraction is mostly to the core rather than each other. Therefore, it's remarkably like a standard 2x2 cube, but that it's translucent and will fall apart more easily (more easily than a 3x3 dicecube too--because it has less than 1/10th as many magnets).
I consider the dicecube (both 3v3 and 2x2) as more of a novelty item than something you would want to use every day, so I don't mind that it's not particularly stable.