Gmail users concerned with security were able to enable SSL connections to their mail for over a year now. A few months ago, Google turned this on by default for all users, problem is, this is only for gmail, not any of the other Google services. This means Calendar and Contacts are still pushed in the clear.
Microsoft have announced today that they have enabled users to turn on SSL which secures the connection between you and Microsoft servers for not only Hotmail, but also Calendar, Contacts, SkyDrive, Photo, Docs, devices.. pretty much everything. At the moment its opt-in, hopefully one the bugs are ironed out, this is in place by default.
To enable HTTPS for your Windows Live, go to https://account.live.com/ManageSSL.