The very productive Cassini mission might attain some indirect information by analyzing the ring arc material--however, it is unlikely to come close to the little moon again before the mission ends in 2017.
Determining the shape of the moon's orbit will help resolve the question of its mysterious origin. A tight circular orbit would indicate that MK 2 is likely the result of a collision between Makemake and another KBO. Conversely, if the moon is in a wide, elongated orbit, it is more likely to be a captured object from the Kuiper Belt. In either case, the event would have probably occurred several billion years ago, in our primeval Solar System.
Now speaking of size within the Solar System, well, let us just say that the Sun is unmatched. Did you know that the Sun comprises more than 99% of the total mass of the entire solar system? Jupiter actually takes up much of the remaining proportion. Surface temperatures on the Sun stand at 5000 Kelvins (4727 degrees Celsius). With temperatures at its core reaching a 15.6 million Kelvins (15.6 million Celsius), the Sun is truly a celestial spectacle. It gets even better when one realizes that the Sun is classified as a class G star. Stars are classified in six major categories that tie in to the surface temperature and brightness. The categories are M, K, G, F, A, B and O listed in ascending order brightness and surface temperature. You can see that the Sun falls on the lower end of this classification. Category B and O are rare in the universe while most stars are in the category M and emit less heat and light energy. That said, the Sun is within the 90th percentile by mass among all stars. We have found other stars that are larger than our sun: one is estimated to be approximately 60,000 times bigger.