I was thinking of a mount system...similar to a hero system. Yes, yes, I know, people will cry "We have a problem with people 'running' from players in PVP, and it'll be used to help low levels run to cities way later in the game." (Shiverpeak mountains, anyone?) I'm thinking of making this mount system unique to this campaign only. So, the mounts are unable to travel with you to foreign lands. I don't know if it could be something like the Junundu, to wear you click on something and you get on your mount (if you have the mount skill available...or if you enter an area your mount appears by you if you select it (like you would a hero), or something like that). Plus, you could make enemies in PVE have horses, whatever. You will still be able to do normal attacks while riding, so you don't have to mount/dismount. I also like the idea of your mount being able to attack, and possibly having skills which I will list below.
I think the mounts can level up with you (similar to heroes). Perhaps every level they earn you can talk to a trainer that will teach your pet/mount a new ability or something. I am sticking with the 8 skill system though...and that goes for BOTH you and your pet. So if you want your pet to have abilities, you will sacrifice some of your own to make room. Of course, mounts will move faster than normal people, which makes them valuable by themselves. However, your mount is attackable while you are on it. If your mount is killed, you need a ranger skill that revives the animal (which would be better than a universal skill which allows you to revive your pet at a pretty big cost...like, half of your HP) Of course, your pet will accumlate DP. I'm not sure how you could program your mount dying if you're on it...I don't want to just appear next to it, maybe make it more realistic? You could lose half of your health, energy, and your skills need to recharge for 5 or 10 seconds if your mount dies while you are on it. Or, you could just make the mount's HP your HP. If it dies, you die. That makes things easer

Examples of mount skills: (these skills are like the Junundu ones...meaning they are fixed and cannot be increased by having points of a certain attribute)
A skill that increases speed for a certain amount of time.
A skill that heals/revives the pet.
Skills unique to the pet's race (probably the elites would go here). (Horse kick, Moa bird peck, I don't know, I'm just throwing ideas.) I know the bear has brutal mauling, something like that.
A skill to speed up the attack rate for a certain amount of time.
I don't want too many because you need skills of your own, too.
Hold on!!! Another idea came to me. You can set up skills when you are riding the mount (8 total, so fighting separately would be stronger than being on it...but some mount skills could deal massive damage to unmounted people. (In a fight, a cavalier has a huge avantage over a footsoldier). That could discourage some people from running from place to place, as well as from always fighting separately. I want people to THINK going into battles, not just charging. I want to discourage Leroy Jenkining...if you know what I mean. So, you can set up the skills (8 combined of you and your pet...it could be 8 pet 0 human, or 8 human 0 pet, I don't care.) while you are riding your mount. Then, when you are off it, you both get your own set of 8 skills.
There's a problem though...heroes. Having heroes with a mount would be insane. You'd have to allow the henchmen to have their own creature or something (with a predetermined set of skills for the mount). That's a lot of things going on at once though. It wouldn't be hard to code the henchmen to mount theirs (if it's alive) when you mount yours, but I'm thinking of cutting down the maximum party size to six.
OR, you could stick to something similar to the junundu, and click something to make your mount(s) appear. (That is, if you have gained the ability...by doing a quest or something). So whenever you dismount, the mount will flee. That would make pets still better over mounts, because pets would actually fight. Your mounts would still have skills you can select (some being determined by your primary profession, maybe) though.
Also, I don't want to be stuck to the ground. In a special mission or part of the final battle, I want to be able to fly (Pegasi, Wyvern, even a dragon, anyone?). Ascending and descending would be difficult to work in, possibly, but I think it would be a really cool/visually pleasing idea. You could pick the skills for both you and your mount (8 total, because you can't really dismount in midair, bad things usually happen). To get rid of the my 8 skills vs. 8 pet skill issue, you could start in the air, and the entire mission could take place there. Your mount's HP becomes your HP, of course. However, I'm not too sure how resurrection would take place. You could have special mid-air things that auto-resurrect all fallen comrades when used (but they only have one use). Another question...how would dying work? Would you and your mount just collapse towards the ground and disappear from view? Or what? Yeah, the more I think about it, the less likely I see this being implemented. It does sound awesome to me though. It adds in a nice little twist. I could just see an elite ability being "Dragon's Breath"-- Insane fire damage to all enemies in the area, causes burning, and visually pleasing to the eye. Recharge time would be at least 60 seconds though.
Sorry about all this, I got new ideas and changed some halfway through.
Synopsis, in my opinion: Cool idea, difficult to implement. But if it could be...@_@