I have to agree with you; I think the oracle is definitely being sneaky about something with Roy's memory. As for Belkar, something undead could make a lot of sense, too.I can't help but think that the oracle did know that Roy would keep his memory, and is being sneaky about something.
Also, I've noticed that the oracle has never used the term "dead" when refering to Belkar. We just know that he "isn't long for this world" and "will draw his last breath". I'm thinking planar travel and/or changing into some non-breathing creature are both options. Than again, maybe he'll just die. A year in-comic lasts a pretty long time IRL.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.