Okay, first of all, it IS possible for the universe to expand faster than the speed of light. Nothing can travel faster than light, true, but the cosmic expansion is the increase in distance between galaxies rather than the movement of galaxies themselves. During the inflation era, for instance, which occurred (far) less than a second after the big bang, the expansion rate was such that something the size of an atom would have been blown up to (more than) the scale of the observable universe today.
Second, the 'light' of the CMB is, more accurately the 'heat' of the universe. Imagine the universe as a room that starts at the same temperature everywhere. This room is so large that the light emitted at one side takes a while to reach you at the centre, so you're effectively seeing into the past. Now imagine that the room starts to get colder. You'll feel the temperature dropping around you straight away, but even though the rest of the room is cooling at the same rate, it looks warmer to you because you're seeing into the past. As time goes on, the area around you will become freezing, but if you look at the room's walls they still seem to be red hot.
This is exactly why we still see the CMB today: The area around us has cooled to almost nothing, but we can still see the surface of last scattering, apparently still hot, in the distance.
Incidentally, despite what Paula claims, the CMB is not a myth. There is no reason that radiation would be at the edge of the universe, traveling away from us at the speed of light, and there is no basis for the claim that it can be explained by cold regions of the IGM. The CMB is extremely well measured, including the minute variations in temperature that occur in the exact same pattern as were predicted using inflationary cosmological theory.