The Shattering vs. Cataclysm

For people who do not currently play World of Warcraft, and/or aren't keeping up to date with all the details, the upcoming "Cataclysm" can be somewhat confusing. What does the Cataclsym mean for you if you don't have a current WoW account, but would like to either try the game for the first time, or come back after a long absence? What exactly do you need to pay?The confusion stems mainly from people associating the name of the new expansion "Cataclysm", with the changes to the world of Azeroth

World of Warkraft...