Speaking of the First's power, I hope Kishimoto uses this to explain something about Konoha's origins. I'll be disappointed if Kishimoto just said that the first had the power to control the bijuu as a deus ex machina. Really it could be one of two things:

1) There is a secret origin story wherein the first uses his awesome bijuu-controlling power to found Konoha.
or...
2) Kishimoto needed someone to be able to control the Kyuubi, and he just pulled somethig out of his ass. "uhh... let's see... I know! I'll tell them that the First Hokage could control the bijuu... and... uh... he's been cloned! That's it! A clone! I'm brilliant."