The upcoming sequel is so huge that it's being released as three separate games. Go do some research, I think you'll be surprised.
I'm not saying Starcraft couldn't be a great MMO, I just believe when comparing it to Warcraft, they made the correct choice. Plus I feel that since they've been making Starcraft 2 for so long they have had the time to write so much more story so maybe after the sequel, it could be on warcraft's level. I also feel that they're doing that just so they can release "3" starcraft games at 60 bucks. Great marketing but it seems overwhelming IMO. Anyway, back on topic. I've been playing wow on and off since its been out. I spent one day reading things on wowwiki learning the lore and I still haven't read everything. It's awesome how much stuff is packed into the game. It stays consistent. The only things that may veer off is when blizzard feels they need to release a new patch and "resurrect" some boss or add some random guy. It sucks when they do it but in the long run, they still create lore that fits and pretty much more than half of wow's base cares about loot anyway.
It's one of those games that I enjoy spending free time on when I have nothing else to do. I moved back home for this upcoming semester so I may see myself playing the new one during that time. Since my first time playing wow, I haven't played it longer than 2 months. (Span of two months, not time played

). It's pretty simple after you level a guy because eventually you will know where everything is. I find it rather enjoyable than tedious but thats just me. (PVPing while leveling may be one of my favorite things in a game).