Asteroid-Man said:

Is there plans to make Anakin disapear out of the Vader Suit like Yoda and Obi-Wan did? It seems like a continuity error to keep his body intact when two scenes later we see he became one with the force. Keeping the burning of the suit still makes sense IMO (Symbolically ridding the evil of Anakin).

Bingowings said:

It's not that much of a continuity problem as Qui-Gon didn't vanish either (he even got burned on a pyre like Anakin).

My taking of the Force-ghost thing is, as explained by Lucas at the end of ROTS, Qui Gon had been studying immortality through the force, Like Darth Plagus the Wise and made his return from the wilderness of death, we are now led to believe that in his return he now communicated with Yoda and Kenobi in their retirement and educated them in immortality. Palpatine was also studying from Plagus's instructions and was passing this knowledge on to his apprentice, Vader, but I don't know what happened, wether Plagus's knowledge was faulted or immortality doesn't apply to Sith, so perhaps when Vader repented by saving his son the knowledge he had acquired was enough for him to become one with the Force.......or is that a load of crap?