I am still relatively new here, but so far I like it a lot, and there really isn't anything I can think of that the mud needs, and maybe somethings I am thinking of have already been implemented, I just don't know about them yet. But for what it is worth, here are a few ideas that could be interesting...
Mounts-I don't know if you have them here or not, maybe even skills such as riding or mounted combat could be added. Religions could get their own mounts, sort of like familiars that you can ride. Riding would likely be limited to outdoors or cavern type settings maybe. Mobs you are fighting against could have a chance to hit the mount or the rider.
Tomes-Maybe some sort of books, they could be one use items that either add a skill or language you didn't have before, or maybe just add a little to an existing one...something that pops maybe just a little more frequently than runestones, certain mobs may have a better chance at having them maybe...also could be class or race specific, or language specific, ie I have a tome that grants a new spell, but since I can't speak/read dragonic, its useless to me.
There was some discussion about people killing kingdom mobs...maybe having mobs cry out when attacked would be a good idea, maybe mob witnesses could file reports with the town guard, without using names, just descriptions to add a little to the RP side of things...'It was a male balrog with violet eyes, black, long hair, a long beard and skin like coal...I did notice a scar across his left eye.' Something just utilizing the basic description of the character.
Some sort of combat arena would also be nice...somewhere that two people could fight against each other, and others could 'watch' maybe even place bets on who would win, a players record could define the 'odds' if people wanted to bet on the person, and bets could be either gold or maybe even quest tokens (those this could be abused if not coded properly and monitored) and perhaps some sort of prize for the winner, nothing extravagent, maybe a little gold, or some tokens, or some sort of enchantment or something.
These are a few to start, may have more later...as I said I like this mud a lot, and i can't say that it NEEDS anything, maybe just somethings to add flavor...