I would love to see more RP blossoming out and about on our beloved server. I have a feeling that a lot of RP'ers are just sticking close to their friends and keeping things secret and quiet. It's hard to motivate others to join in if you don't make it possible for that to happen!
Here are some ideas & motivators to help RP re-emerge...
...and to keep it going once it does!
1. Use an RP addon like MyRolePlay (MRP) to build your character and show others that you roleplay. This will also help you find fellow roleplayers by being able to see the addon active on those around you. Try to keep away from majorly dramatic, over-the-top or God-moding descriptions. Keep it simple and fun. Also keep some things mysterious. If you put your entire life story for your character out there, there's nothing for others to discover!
2. Try using some creative /emote options handy. Write something up for yourself for when you're crafting, fishing, checking your mail, your bank, repairing your gear, etc. Also try to come up with something that might be fun to use OUTSIDE of town - perhaps get creative with your mounts. Why not make an action like you're literally calling out for your hunter pet? Set up emotes like this in macros and have them on your bar. You never know who you might find if you show that you're immersing yourself in the game!
3. If you DO start some RP, don't be clique-ish or act like a wallflower. This is one of the reasons that non-RP'ers are put off. RP can be intimidating to 'put out there' for others to see. But if you keep it fun and immersive, and if you keep yourself OPEN to others walking up to join in, it could help spread interest. Don't keep it private (unless you really want to) but don't be afraid to toss an emote out there to see if a fellow RP'er is interested in striking something up.
4. If you play your characters with an extreme personality, be careful. This is another cause for non-RP'ers to hate roleplay. Mean, snobby, or otherwise unfriendly behavior could easily be taken the wrong way, even when RP'ing. It's best to keep things like this lighter until you get to know others who are interested in RP'ing with you. Nothing pushes someone away faster than an RP'er whose character is abrasive.
5. Don't be the RP police. In fact, it's best to steer away from such a strict mindset. It's okay to quietly & kindly guide someone in RP if you think their storyline or what-have-you is WAY off from being plausible in the game, but don't be a jerk about it. WoW is very, very deep as far as history and storylines go. It's very realistic to think that some people might not know the exact timeline or details, even if they've tried to research it. I, for one, am a prime example of that. Instead of snubbing your nose at them, help them out.
6. Don't RP like you're a high-and-mighty character that deserves a red carpet and kingdom of your own. This is THE number one way to cause hatred of RP. No 'Mary Sue' attitudes. Your character is not the child of Arthas, you didn't have a love-affair with Sylvanas, and you're not a vampire. There's nothing wrong with secretly thinking these things, but putting them out there might really detract people from wanting to RP with you at all.
7. There are different types of RP. There are some that do random walk-up RP with others. Some actively RP action as they do things like hunt and quest. Others might just have RP discussions in town. Others still might have a detailed back-history & personality for their character (and they might also follow a pre-built story as they RP), while some might simply be immersive by 'getting into' the game. Be open and accepting of different kinds of roleplay.
8. If your RP goes a... *cough*... sexual direction, keep it to yourself. Put yourself in a party and keep things quiet. Believe it or not, there are other people around you that might not want to see it, and it can actually give the general RP community a really, REALLY bad name.
9. If you do roleplay, try to keep yourself in character when you're actively RP'ing. Avoid talking about unrelated things (i.e. 'real world' stuff), and put anything like that in brackets or preceded by 'OOC' so you don't mix up the flow of things. This goes along with my RP police statement, though. If you see someone slipping, don't slam them for it. It would be best to gently guide them to do otherwise. Be patient!
I think this is a good springboard for RP'ers old and new. The BIGGEST thing I can stress is to be OPEN. Don't push people away, don't be afraid to look for people, and don't be dramatic. Keep things fun and encourage others to join you!
If anyone has any tips to add, feel free. :-)