Been playing a new online game. After 30 hours played I'm level 13, so kind of a rough leveling curve. As you may have divined from the title, it is not an MMORPG, or an RPG at all. It's Battlefield : Bad Company 2, a first-person shooter. And the leveling system is pretty cool -- cooler, in fact, than the leveling system in any MMORPG I've played.
Not without reason, of course : MMORPG's generally offer advancement outside of leveling, where there's very little advancement outside leveling in BFBC2. But you would expect that WoW's leveling system would wipe the floor with a mere FPS, and it does not.
BFBC2 has two big advantages. Well, three if you count that shooting electronic guys in the face is way more fun than pressing a "1" button to cast a spell against a placid monster that presents zero threat to you and is only there to be killed.
You get "base" XP for killing enemy players. But you also get all sorts of bonus XP for exhibiting "skill" or group-friendly behavior. You get extra points for headshots, extra points for assists, and all sorts of extra points for assisting your teammates (and especially your squadmates) instead of being off on your own. Unlike the way WoW often works, there are a lot of very immediate rewards for constructive social behavior.
Next are pins. Pins are a lot like achievements in WoW, except that you can be awarded pins multiple times, and they award bonus XP. If I get four shotgun kills in a match, I get a pin and 100 bonus XP. If I do seven repairs in a match, I get a pin and 100 bonus XP. In fact, if I were to do either of those twice in a match (eight shotgun kills or fourteen repairs) I would get 2 pins and 200 bonus XP.
Finally there are awards. Awards are cumulative and give large XP bonuses for milestones like 500 headshots or 100 knife kills or for earning a "medal" (bronze/silver/gold/platinum) on a particular weapon.
A similar system in WoW could provide bonus XP, badges, or gold to reward excellence in play and constructive group play. For example, you could receive a ten badge "bonus" for beating 100 (non-consecutive) bosses without dying during the fight, or a bonus for getting through 100 bosses without a death in your group.
Of course, it isn't merely the bonuses that make advancing fun, there's also the way it is presented. At the end of every match you are shown a bar with your experience before the match, then watch as it is filled up with all the XP from the match, as well as all the pins, awards, and achievements from the match. It provides a nice sense of accomplishment and is much better than the feedback in WoW, which tells you where you are at in your progression, but rarely tells you what you've accomplished during that particular play session.