Burning people makes sense, but does it actually heal someone? Or even bring him back? I thought Tararyen were simple immune to it. That'd a fantastic scene to start off the season of course and to solve that theory.
Does anyone remember Viserys? He was of the exact same genetic heritage as Daenerys, without any Stark admixture in the blood. Numerous Targaryens were harmed or killed by fire (most notably, the Mad King's grandfather and uncles, as well as King Aegon II, his aunt Princess Rhaenys, possibly her grandson, Prince Lucerys Velaryon [at least half-Targaryen, like Jon], and Alyn Oakenfist, whose brother was a dragonrider, but who bore the scars of dragonfire all his life) and killed by dragons too. It is not a guarantee of anything, and if a funeral pyre brings a Targaryen back to life, you'd think it would have happened before now, since that is their traditional funeral rite, like the ironborn getting tossed into the sea, or the Tullys on the rivers.
The much more likely mechanism of Jon's survival would be Melisandre's presence at Castle Black, since she is a priest of the same god as Thoros of Myr, and having met Beric Dondarrion, is certainly aware of the possibility, as well as being short a front-man.
“Tolerance is the virtue of the man without convictions.” GK Chesteron
Inde muagdhe Aes Sedai misain ye!
Deus Vult!
*MySmiley*