What is unusual is when a game company publicly endorses such behavior. Star Vault, the independent developers of the PvP sandbox title Mortal Online, has set up an invitation-only forum called the Council of Patriarchs, wherein guild leaders (and only guild leaders) can interact with developers regarding larger game matters. While it isn't unusual to solicit player feedback, it is interesting that the forum is not visible to most paying customers. Whether or not it was Star Vault's intention to open up an "us versus them" can of worms, discussion on the official boards is currently trending towards the divide between solo and group/guild players.
Mortal Online isn't the first game to dip its toes into the exclusive forum club. Some of you may recall that Matrix Online had a private retreat known as the Champagne Room, which, while similar in catering to a small subset of players, was not publicly advertised by the developers.