That could be correct, but I think it will have something to do with their destiny. Yoda, Obi-Wan, and Anakin(It was Vaders suit not the body of Anakin that was burned) had fulfilled their destinies and Qui-Gon did not. Lucas has said this will be explained in the next 2 films. He did say it had something to do with the line "If you strike me down now, I will become more powerful than you can possibly imagine...", so who knows?
accepting death
ok, actually...when I was reading the ep I novel...at the scene where qui gon is separated from maul by the endery wall...he started to prepar mentally for death and become 'one with the force'(kneeling down and meditating..)
then sort of changed his mind and thought he had the ability to defeat maul and came out strong and fierce.....but it was what maul was hoping for....maul was holding back so he could kill him with a 'mortal blow'.....it's a more serious death or something...
it was a trap
(the burning of the jedi body is a cleansing of the soul, but obi wan did not get that honer...and I don't think it will help qui gon come back at all)