I like The Onion, but I rarely find myself reading much of it because the full text rarely improves on the headlines. You might need to read the first paragraph to see where they are taking the joke, but stringing it out for 1000 words does not add much to the first 5 seconds. (I might take this as an object lesson, but look at me go, still typing.)
Syp finds the same problem with Star Trek Online, I said the same thing about LotRO skirmishes, and many of us have said the same about Borderlands and Torchlight: it is great at first, but there is not all that much improvement or variation over time. (I do credit the two single-player games for having interesting boss fights mixed into the repetition, where MMOs tend to rely on even more repetition, even in tank-and-spank bosses.) I appreciate being able to get 95% of the benefit in 5% of the time. Portal did that brilliantly and then ended.
Non-MMO inspiration banished to the first comment.