In Dragonspyre, we hatch a drake, train it, ride it to the top of Dragonspyre, then abandon it (i dont actually know if we ride it only once in the storyline, i'm still in Celestia). Didn't they say something about a dragon rider and his drake are forever bonded? We only use him to take us up to Malistaire's lair, he serves no other use.
So wouldn't it be nice to be reunited with the drake? Maybe when we get to a high enough level, we could get the drake as a permanent mount from a quest. I think its only fair if the dragon is no trade.