I'm on a slow morphine drip of WoW where I can only play 30-60 minutes a night due to being a new father and it's actually really improved my outlook on the game.
I'd written WoW off completely after about one month into Cata as my friends were quitting en masse and I just didn't feel like going through the same old routine again. Nearly two years later, the Thanksgiving sale with Pandaria for $15 / Collector's Edition for $35 caught my eye last month and I figured I'd resub for a month and see what had become of the game (I'd heard a lot of people saying it was great if you played casually, which is where I'm at these days).
So much has changed and so many new systems have been introduced since I last played that I've actually got that sense of exploring the unknown back, just like the good old days of Vanilla where Onyxia was some mysterious rumor and I didn't yet know the entire game inside and out. I know that Transmog is a thing but haven't yet figured out how to do it or started running old content to collect cosmetic gear. LFR, pet battles, brawler's, challenge modes.. I know a little bit about these things from reading forums and MMO Champ but haven't experienced them at all yet. Account-bound mounts, pets, titles and achievements are a big quality of life improvement that didn't exist the last time I played.
I guess I'm fortunate that the playstyle I've been forced into seems to be what the game is targeted towards these days. For me it seems like consuming WoW in smaller portions is the way to go.. I definitely went through cycles in the past, especially raiding in Vanilla/TBC/WOTLK of playing 20-30 hours a week, getting burned out/frustrated, and quitting because the game was tedious and I felt like I was just doing the same stuff over and over again. It's cool to know that I still have a lot of content to look forward to again and feel like the game has something new to show me.