If I were you, I'd use TCGOne to test it before you actually build it. EX's/Mega's are still expensive, even the under used ones. So if you wanna build a deck that's mostly just fun/not tested fully, I think that's a better option. That or PTCGO, but TCGOne is free, so ya know.
I really like PTCGO more, but cards on there can be annoying to get sometimes. I've been testing it with bats on TCG One and it was just rather clunky. I'm going to probably make a post later about the deck.
Back on topic though; I don't see many new decks popping up until another set after AOR, three the most. Most of the decks I've seen people talk about I think are going to be widely tech'ed in many different ways because the new set gives a lot of versatility to the format, Standard and Expanded.