Ultimately, I do not know what happened. As such, the best I can say is that either it is exactly what witnesses claim, the crash of an extraterrestrial craft, or it is another top-secret program the military doesn't want the public to know about. I can say that I am very skeptical of the project mogul and crash test dummies explanations.
If what occurred was indeed the crash of an extraterrestrial craft then I believe the secrecy surrounding the incident can best be attributed to 2 factors, the advantages of such technology and the fear of mass panic. Any nation who can recover actual extraterrestrial wreckage would have a great advantage over other nations. As far as the fear of mass panic goes, this is the year 2010 and despite our advances millions of U.S. citizens are outright hostile to scientific advancement. For example, roughly 50 million Americans subscribe to the belief in the Secret Rapture. In my opinion, this is 50 million potential people at risk for succumbing to mass panic.
So do I think society is ready for the knowledge of the existence of intelligent extraterrestrials eons more advanced than humans? Absolutely not. Many individuals simply cannot handle the truth. Their whole world is based around a religious interpretation of reality, one in which mankind plays the central role. Anything that threatens to destroy that world-view will send believers into a panic. Perhaps in another 63 years society will have advanced to a point where people can accept the truth. In the long-run I think it really doesn't matter how society would handle the truth as I do not believe that the U.S. government will ever admit to the truth, assuming that an extraterrestrial craft did indeed crash in 1947.
I do not believe in government disclosure. I do not believe there is a plan to condition society into the acceptance of extraterrestrial life. If the Roswell event was extraterrestrial in nature, then I think the decision was made to cover-up the truth without ever a plan to inform the public at any future date. I strongly believe individuals in the know are now simply waiting for the last witnesses to die off so the cover-up can be complete.
UPDATE: My opinions have slightly changed since I first posted this last year. I lean more toward the extraterrestrial explanation. As I apply logic to the events that transpired I conclude that the military was not covering up the crash of any other experimental craft, mainly because the technology of 1947 would not warrant such a conspiracy 64 years later. Likewise I simply cannot fathom any other secret program that the witnesses would confuse for the crash of an alien craft complete with alien bodies. Therefore, I am forced to logically conclude that the first story revealed by the military that a "flying disk" crashed was the correct version. The subsequent cover-stories and lies generated by the military were done specifically to conceal the truth from the American public.
I now believe full-heatedly that the military is simply waiting for all witnesses and their spouses and family members to die so that the cover-up can officially be complete.