Well, I wouldn't put money on Dalamar, as he's more a Dragonlance character, yes? (TBH, this is the first I've heard of him)That's no help!! Mordenkainen, Elminster, Dalamar and the Simbul are all cool. LOL
If I were to guess, of the four I'd expect Mordenkainen to get a card. He's probably getting a spell or two in the set with his name anyway, I think he'll take the blue planeswalker slot.