Imaro
Legend
Think about it this way. If Dragonlance was the setting, wouldn't it make more sense to wait until the Dragonlance books come out to put draconians out there? After all, they're an iconic monster race for Dragonlance.
The funny thing is that 4e's philosophy of everything is core, makes me wonder about this. I mean, The Warforged appeared in Dragon (even though we knew Eberron would be the second setting released and that they were as intrinsic to it as draconians are to Dragonlance) and WotC had no compunctions about turning around and printing them again in the EPG.
While I don't think they will reprint the same info in both books, the new philosophy along with the singular nature of mosters, means they could easily print some "monster" draconians in the Draconomicon 2 but turn around and put different "monster" draconians in Dragonlance... along with rules to make them a playable race. That way you aren't necessarily slighted by purchasing the DLPG & DLCG without the Draconomicon 2... but it sure creates an incentive for a DL DM to invest in it.