The encounters in WoW are better than they've EVER been at any point in the game. Unfortunately, they're running up against a wall - which is the skill level of the playerbase. It's hard to make hard mechanics when you know 90% of your playerbase can't do them.
WoW is probably a better game now than it ever has been as well. PvE balance is about as good as it can get. The new raid finder is something interesting to do (and hilarious watching terrible people try and do easy mechanics). The newest dungeons are a blast and filled with
amusing lore. Again, the raids are very well tuned, at least in 25 man, and undertuned in 10's to allow more people to access them. They just implemented a new darkmoon faire, which again gives people more stuff to do.
Unfortunately, WoW is just showing its age. People do get bored looking at the same UI and the same abilities after 7 years, regardless of the rest of the game. Even the best classics (like NHL 94 or golden eye) lose players over time.
SWTOR is a great game too. I am very excited for it just to play in a new world, with new rules and new mechanics. I think the low level game is very polished, which will buy them ample time to fix bugs and deal with game-breaking issues. The base of which they do storytelling and lore is also revolutionary - with a focus on story instances (where they can tune solo adventures), while tying it back into the multiplayer world. Because of that, they can add a lot of new story content whenever they want to.
December 15-20 cannot come soon enough.