I actually see room for two distinct forms of mentorship - IC and OOC. I honestly prefer to keep them fairly separate but I do agree that each form of mentoring should be accessible in game.
I think IC mentoring can, and should, be handled in game using the tools already present. It is just a matter of experienced players having their experienced characters help the characters of new players as appropriate. Of course not every character will be motivated to receive or give help and these relationships should fit existing RP. Just being open to offering a helping hand is he key piece here.
Access to OOC mentoring is what I think is missing here and I really like the idea of an island wide system that maintains anonymity as much as possible. My thoughts on how it could look:
One Possibility:
1. Players have the option of becoming a mentor on a character by character basis. This can simply be a "Become a Menor"/"Stop Mentoring" toggle button or a "Be a Mentor" check box placed in a logical location.
a. Though you enable mentoring on a character by character basis, the player is the mentor - not the character.
b. When you turn on mentoring for a specific character you are saying "I the player want to be a mentor for the island this character is currently on and want all mentor messages to appear in this characters message queue."
c. The become a mentor option might be better placed in the player info section though it would still be good if the player could decide which islands they want to mentor on and which characters receive mentor messages.
2. As long as there is at least one character is a mentor on the island, "Mentors" is a potential recipient when sending messages.
a. It is only possible to send OOC messages to mentors
b. It is not possible to send messages to mentors and other recipients at the same time
c. Messages sent to Mentors are signed "Asker"
3. Any message sent Mentors by all characters show up in the message queues of all Mentors as defined in step 1.
a. Though the mentors can not see who the sent the message, they can respond to it like any other message.
b. Responses are sent to the asking player and all other mentors
c. Messages from mentors can only be OOC messages
d. Messages from mentors are signed "Mentors"
Another Option:
1. Players have the choice of joining the "Help" group on a character by character basis. This can simply be a "Join Help Group"/"Leave Help Group" toggle button or a "Seand and Receive Help Messages" check box placed in a logical location.
a. Though you enable Help groups on a character by character basis, the player is the helper or asker - not the character.
b. When a specific character of yours joins the Help group "I the player want to be be able to ask/answer OOC questions for the island this character is currently on and want all Help messages to appear in this characters message queue."
2. Once a part of the group, "Help" becomes a potential recipient when sending messages.
a. It is only possible to send OOC messages to the Help group
b. It is not possible to send messages to the Help group and other recipients at the same time
c. Messages to the Help group are all signed "Anonymous".
3. Any message sent the Help group show up in the message queues of characters who have joined the Help group per step 1.
a. Though you can not see who the sent the message, you can respond to it like any other message.
b. Responses are sent to all characters in the Help group
c. Responses can only be OOC messages
d. Responses are all signed "Anonymous".
Just my thought!