Unlike some people, I do not regret the time I spent playing WoW. I had a lot of fun and I met a great deal of interesting individuals that I otherwise never would have met. Overall, it was an experience that I wouldn't have wanted to pass on.
Having said that, while Cataclysm seems to be brining much needed changes to WoW and overall looks like an interesting expansion, I will still not reactivate my account and buy the expansion. One thing that I have learned since I have stopped playing WoW is how many games I have been missing out on. While there is nothing wrong with paying for an MMO, it does tend to force you to commit yourself financially to it. As a result, if you tend to be low on cash, you end up not having the money to play anything else.
Overall, as I said, I do not regret the time I spent playing WoW and I will be observing how these changes unfold. But mere observation is where it ends for me, beacuse I want to spend my money on new games and new experiences.