I have a confession to make. Over the past few months, I've been putting RuneScape aside in favor of games where death isn't just a minor inconvenience, whether because of game mechanics or from a self-imposed challenge.
That's not to say that these death mechanics would work with RuneScape without some fairly major changes, nor would it work at all if it was the game's only mode. The community does not like drastic changes, and in this case they would probably be right. However, with the right changes permanent death could work well as an alternate game mode, similar to RuneScape Classic or the upcoming 2007 servers.
In short, everybody would start from scratch and the main goal would be to last as long as you can. Think of it as RuneScape: hard mode; when you die, you start over on the same account
Training would be a lot faster, of course, because something as common as a lag spike would reset your progress. Progress on these servers wouldn't be tracked by experience, but by risk. Activities would give points based on risk, the total of which would appear on the high scores: a player who reached 99 mining from iron in a safe area would have a lower rank than one who trained in the wilderness or an area with many aggressive monsters or one unlocked from a difficult quest. Training combat would be faster still, and all monsters, up to and including bosses, would be both stronger and more aggressive, with better drops as appropriate. It would be dangerous, with rewards to match. Naturally, the greatest rewards would come from PvP, as we learned years ago that NPCs are nowhere near as dangerous as other players, and it would finally make the wilderness a place to fear again.
The most important question is "why": what is the point of a server where nothing you do will last? The answer is that it would simply be a challenge akin to DIY and skiller accounts, though one that will run on the same account and a separate server. Players today complain about how much of the game is "safe" compared to a few short years ago, on these servers it will not be, and they would develop a metagame and economy built around danger: whether it's the best way to progress, and the best items for combat or defense. In short, a new game.
Of course, this game mode isn't perfect by any means. It would not appeal to skillers or players that prefer a relaxed atmosphere (to put it lightly), and it would undoubtedly be filled with the kind of griefing that the wilderness was infamous for years ago. Furthermore, the amount of work it would take to accommodate these changes is work that could be better spent improving the main game, and if it fails, it will all be wasted.
Still, it's a topic that is at least worthy of thought for players that have grown complacent, if not for Jagex.