Yes, if you log in with a Live account (not necessarily a hotmail account), then it is all stored for you. I have a Live account from TechNet and my Xbox ID, etc. I don't have a live.com or hotmail.com e-mail address though, so it's important for me to specify that this is not something through Hotmail. When you install Windows Live Mail, in the upper right, you can choose to log in with a Live ID. If you do, and do so on all other computers using WLM, you'll have a synced contacts list and calendar.