Now just in case the title gets blown out of proportion, other than cutting edge progression, I'm pretty sure that boomkins aren't necessarily required this tier.
Our guild (5/10M) has a very high performing Boomkin, and in the end we'd all prefer if he'd stay on his Druid, but he has interests in swapping to a Shadow Priest or Restoration Shaman. He would stay Boomkin if needed I believe.
How are Boomkins looking next tier? Do they have fights like Kromog and Beastlord where they're particularly strong on? In the end would it really matter if we had zero Boomkins?
Sorry if this answer is somewhere on these forums, I stick to the warrior forums.