Rested XP + Stacked heirlooms + Guild leveling perk + LFD chain dungeon runs = my leveling dream come true, especially to get through the old-hat 60-80 zones. I'm bouncing back and forth between a bunch of alts and loving it.
I love dungeon runs for leveling; it's fast, you get new gear, you don't feel it go by, you can get a bevy of quests done at the same time if it's your first time in a dungeon on that character for even more XP, and for me, the group dynamic (which is the main reason I play the game after all) is always active. Questing just gets so boring unless they're really fresh new ideas or new areas like my first time through a zone. I never seem to tire of dungeon runs though unless I happen to get the same dungeon in a queue twice or three times in a row.
I appreciate how the social aspect of party building and server reputation have all gone down the shitter due to cross-realm queueing, but it's been a fair trade off to get groups going as fast as possible. And at the end of the day, Blizzard's succeeding with players like me; I wouldn't still be subbing and playing if they didn't expedite leveling like this, even if parts of the social experience have been gutted. I'm of the opinion that I experienced them over the last 5 years and I don't mind that some of them are gone now. I still have my guild, and with my goal just being to develop and cap new characters, the game's working for me at this point.
Anyway, really love trying out new characters and specs. The mage is 84 now, and man, is Fire ever the most fun I've ever had DPSing in this game. So great!
And yeah, this has all made leveling much more than it's ever been imo, but I'm definitely still in the camp that feels and believes that the game really begins at level cap. I can't wait to get a character to cap and start getting involved in tougher 5mans and raids.
Pandaria's challenge modes, timed runs, etc. and more end-game content are a dream come true for a WoW nut like me, haha.
One of these days I'll level/develop a melee/tanking character. So far it's just been ranged/healing I've clicked with.