A question: why no 25v25 BG?
It makes no sense to me that Blizzard havn't made a 25v25 BG given that 25 man is their prefered raid size for PvE. Especially with the introduction of rated BGs in cataclysm hopefully turning BGs into their real e-sport. I mean lets be honest, how many more people would watch a Paragon Vs. Ensidia (yes I know PvE != PvP but in terms of mass coordination I'm sure they're top) 25v25 BG compared to their arena tournaments? I would guess a hell of a lot more.
I also know that the 10 man guild that I am going to co-run is going to do rated BGs on off nights or after raid time and I would guess that 25 man guilds would want to too; but they currently lack a way to do that without having to drop people or by having a (massive) roster.
I really cannot understand this. The vast majority of people I have ever raided with have at least done casual BGs to flex their PvE-oneshot-peen, and certainly would be more inclined to with their entire raid going. Hell my last guild celebrated its 1 year anniversary a few months back by taking and holding a pub in Stormwind for 3 hours (horde guild) and it was one of the most enjoyable times I've ever had on WoW.