I would start developing a version that is not web based, cut down the number of servers on the website and make web based playing f2p/p2p. Members can download the game from the website (lets call it rs3) but the price of membership would be bumped up to 10-12$. The downloaded game plays similar to WOW but is not WOW..it keeps the feel of runescape.
I like the idea of a couple of 2006 servers, and of course, all of the shitty updates will be gone. More bosses, skills, and quests would be released and tied in together more smoothly.
I would also introduce the runescape lottery. 1k a ticket and a limit of 5 tickets per player.