I would worry about the security of whatever was caching my password...i doubt MS uses strong encryption for your saved password ..I have a feeling that they are probably in plain text some where....but if its stored locally on the machine, well its not that hard to make sure none sits down at your machine and uses it, so the cached password wouldn't be that bad.

Example, at my office every one has a laptop, the laptop bay it sits in has a locking door, so if we don’t take our laptop with us, the system is physically locked away.