IF your an old or new player, it really throws alot of differnet quests and such that you only will see with the Wrath of the Lich King.
Now the new expansion offers so much NEW content that hasn't been done in the past. You can pretty much play solo and make your way through quests and when you have more time to play join a group and raid some dungeons. I think WoW is a good starter MMORPG as its a little more fast paced then some of the other titles. Games is sorta what saved me BUT they get very addicting and I tend to dream about them.(Need a gamer chick) LOL. Now for me I was heading down the wrong path in life. You can play for one hour a day or 8 hours a day and still have tons of things to do. Every Online game to me is a huge time killer.