It doesn't matter to me if mentoring is IC or OOC. But it should not be realm-based. Too many realms don't have good mentors. All new players should have access to as wide a range of mentors as possible.
One possible issue with an island-wide mentors guild is that it could become an avenue for communication by experienced players. Guilds are often used to facilitate communication, and many people routinely join as many guilds as possible for that reason. How could we control that, to prevent from being just another avenue of communication and propaganda?
If we do it forum-based, then we would be forcing players to join and use the forums.
