Hardcore Casual recently ran an article describing MMO quests as lackluster (my paraphrase). Whether it is the difference between trivial tasks (kill some rats) and epic quests (change the world), or the text we all ignore since we really dont care about an NPC's starving family, we just want to level and move on.
The author touches upon the possibility of putting in some random rewards. Sometimes gold. Sometimes gear. Sometimes...an XP boost.
And that last one hit a chord with me.
WoW is the first game I ever played where the expansion packs require you to PLAY the original game plus all earlier expansion packs.
Many games require you to BUY and INSTALL the original, because the companies want to get paid, but to play the expansion pack, you can jump right in and play the expansion pack.
MMO is different. They require you to buy, install, and PLAY all past versions of the game before you can start playing the xpac.
And the parts of the old versions that you generally get to play are the (my opinion) less exciting ones. For a large group of the player base, the end game is where the fun is at. Questing and leveling provide some entertainment, but often are viewed as an obstacle in the way of the end game. When you want to play the expansion pack, you don't pause to enjoy the classic raids at the appropriate level, since everybody else is playing the new expansion's end game and in a social game, you pretty much need to be at the same general point as a large group of other people.
Blizzard seems to acknowledge this so they reduced the XP needed to level in classic, and then TBC levels. They invented recruit-a-friend so you can sucker in other paying subscribers and help them fastforward through the obsolete content (or triple box your way to a half baker's dozen level 60's). If you want to play an alt, you can Death Knight it up and hop in at 55. Still only applying to your own alts, there is the 10% increase in XP from heirloom shoulders.
Seems that they realize nobody wants to play the old games as much as they want to play the new game. What a revelation??!!??
I doubt they'd build a Death Knight-like path for every class (do some entry level stuff to learn the very basics, and then enter the world at 55 or some other fast-forward point), which would be nice, IMO, even for new players.
But, maybe just add in an optional Quest Reward on all quests that currently allow you an option of gear or potions or whatever.
I'd choose "Nice Chunk of XP" as the reward every time, especially when playing a toon that's getting a free ride through quests by their big sister level 80 toon, and therefore does not need any gear.