World of Warcraft at Ten Ton Hammer

I was reading some blogs today, and I know by doing so I'm just asking for trouble, but the hot topic is all about Aion lately since the beta events and their NDA is up. People are tossing and turning over the upcoming release of NCSoft's new game, and oddly to me the biggest topic doesn't seem to be about the game's assets but rather just how similar or dissimilar it is from World of Warcraft.

Since the release of Blizzard's behemoth, this seems to be the running debate with each new release. What I don't understand is... why does it matter? Innovation has long been a slow drip and not a busted open drain pipe, flooding the scene immediately. Let it happen, and worry whether the game can rest on its own merits.