I kinda see a problem with Kyurem changing form.
When Kyurem changes form its implied it absorbs energy from  Zekrom/Reshiram. Now its just speculation until we see how it changes,  but being able to change into one form means it should have the  capability to turn into the other in both games. Meaning both Reshiram  and Zekrom are still part of the story. So why bother making 2 different  games?
I'm interested to see how GF'll handle this.
~~~~~ Sophisticated Ignorance
		 
Well it's implied that Kyurem is absorbing the power of N's Reshiram/Zekrom which is why the version legendaries reversed from BW1. N took a different legend in each game, so having 2 games makes sense. Black 2 continues the story of Black basically. Since you caught one of the legendaries in BW, I'm gonna guess that you can only get 1 form of Kyurem per game. I highly doubt that Hilda or Hilbert are going to let you borrow their Zekrom/Reshiram's power. It would be like Red making an in-game trade with Ethan.
The real question is why N lets Kyurem take Resh/Zek's (I'm tired of typing them both) power. ..Damn, BW really is the first time anyone's cared about story in Pokemon... Good job, GF.
@ Charon
Pretty much everything you said was covered on page 45.
The ice is Kyurem's actual body. Like I said before, appearance has little to nothing to do with typing. (Blastoise would be Water/Steel, Charizard would be a Dragon, & Regigigas would be a Grass-type)
"Secondary-typing" is a fan term. Placement of typing means nothing.
It wouldn't make sense from a game-play perspective if Kyurem's forms have better stats than Kyurem, Zekrom, AND Reshiram. (Which those 20 Base Stat Points would do) Zekrom, Reshiram, & Kyurem already have a balance in stats with Kyurem being the the fastest with the most HP, Reshiram having the highest Sp.Atk & Sp.Def, & Zekrom having the highest Attack & Defense. Without that Black & White Kyurem would just be...well, Reshiram & Zekrom with an altered move-pool & better HP/Speed. The missing 20 is most likely due to balancing for pretty obvious reasons. Believe it or not, but GF actually does try to balance the game.