Sidekick idea exists in DAoC too btw Cryn they stuck it in some patch ages ago, DAoC's implementation isn't fantastic though but then I've never tried CoH's

One thing to note is that a lot of these ideas posted are working largely on the assumption games follow the linear system of levelling that DAoC, WoW etc. use, UO's horizontal levelling method where there are no levels, you just get 700 skill points and can fill them up with a choice of about 30 different skills by actually using those skills - things like healing, poisoning, stealing, magery, tinkering, archery, swords, barding, taming, parrying etc. Meant you could have a far more diverse range of characters yet a newbie character with immensly high skill at the game could still beat a crappy longer term player using his low level spells because they didn't outright miss or fail to effect people higher than them, they just did like 5% - 10% damage instead of like 40% that some of the higher level spells did, other things like having fixed cast speeds giving people time to think, i.e. chuck a fast casting small low damage fireball at someone to try and interrupt their slow casting high damage spell etc. It had all the novelty skills WoW stole too like fishing which was pretty amusing at high levels cos you could go sea fishing and sometimes accidently drag up a sea monster which had decent loot on it and such

Another favourite was the tinkering skill let you do amusing stuff like attach an explosive trap to a box.
I'm not really much of a fan of the linear levelling system in DAoC/WoW etc. but it seems the only choice in most games now. Levelling skills like in UO by actually making use of them meant you could play the game and have fun from the off - none of this spending months to be competitive bs yet without leaving you no way to progress your character - there was still a perfect balance of that. It's just a shame EA broke UO with it's ninja's and whatever, they tried to squeeze classes (that made no sense in UO's lore even) into a non-class based game.