I am not sure, but I belive or don't remember that app would automaticly start downloading updates (4GB at the time of the writing) without asking me first on previous os x releases? What if I dont want to update my current version or I need to preserve my battery? I would aspect this behaviour from Windows but is Mac really copying bad stuff? I was working on coding web site and I had around 15% of battery left then all of suden my mac shuts down because battery was depleted (it didnt even popup the warning because it was buisy searching, downloading and installing iMovie and Xcode updates withouth even notiifieing me). I could have lost serious amount of data or corrupt files if I would be in the middle of data transfer. Is there a way to turn this bad behaviour off?