Three words on the Dragon symbol: EPIC. FRIGGING. WIN.
Seriously, I am so psyched out about Dragon Selection that it's pretty much all I talk about it for three days straight after hearing a piece of news. Latios + Latias EX (maybe with abilities that help each other) would be a dream come true, and if they are actually playable...don't even get me started.
I think the set will include all dragon types that have been colorless in the TCG before. For example, I doubt that guys like Dialga and Palkia (although that would be sick too) will be featured in the set,especially since all Dialga and Palkia cards have been metal and water, respectively. That would mean no Reshiram, Zekrom, or Kyurem, but I am totally fine with that (they've been in the spotlight enough already). Anyways, can't wait to see this set!
As for Raikou EX... I love it. Not sure how well it will do, but it has potential and is a lot better then Entei. Can't wait for Dark Rush, either!