The trouble I've seen with some of the in-game RPs I've seen so far is the logistics of it: do you just advertise a time and location you'll be playing each day, or rolecast and add your players to your friendlist in hopes that you'll be on at the same time? Do you costume up, or play what you like regardless of what you're wearing? Do you stay in Haven or head into the Clockworks? Are you roleplaying an SK storyline, or just using the game client to play a different sort of story? Is there a minimum and/or maximum number of player's you'd like to be involved? Are you going to play something new each session or have a cohesive, long-running story? How do you want to handle combat?

Those are a lot of decisions to make that I think people who set up these in-game rp threads tend to neglect before asking others to play. The last in-game rp thread that I tried to joined was going to end up going into the Clockworks, and really came off as a badly-disguised attempt to get a higher-tier player to carry the thread maker through their missions. The person kept walking away to do whatever, and I was turned off of it fairly quickly (I un-friended them, as I no longer had any desire to play the game).

If you'd really like to get something started, I would suggest thinking of exactly how you'd like it done, posting up a bit of a story to start, and putting down some times that you expect to be playing on a regular basis. Ask prospective players to do the same so that even if you're not on, they can play with each other when there is overlap between some of the their availabilities. If you want to do a cohesive storyline, designate mods from different timezones you trust and have people either re-type or screenshot the chat part of the roleplay in the thread so that other players can see what they missed (this part is a little hard because of how SK's chat box is set up).

Running a successful roleplay can be a lot of work and require some dedicated support, but it can also be very rewarding and a lot of fun.

The only real problem with that is that the number of Haven instances there are is dynamic- the number shrinks and grows according to server load. So on a super quiet holiday when there are few people playing, you may only have English Haven 1-6, and maybe the load on each of them are green or yellow. On a really busy day when there's an event going on or something, you may have 19 or so English Havens, and more than half of them are red. Choosing one specific Haven and hoping that it will be otherwise unoccupied on any given day would really be a gamble, and designating a specific Haven as a permanent RP Haven ... I'm not sure how well it would work.

Really, as much as the Treasure Vault crew loves rolecasting for fanfictions, most of the people who create the characters are happy to wash their hands of actually having to do anything with them. You'd have a difficult time, at best, encouraging spontaneous roleplay unless it was of the silly, incoherent variety. It's not that I'm not in favor of roleplaying (just about anyone in the TV would be able to tell you that I love it), it's just that your player population on Spiral Knights is very different than that of WoW and you can't expect then to want to indulge in the same activities in the same way.