In the image below from what appears to be a Samsung employee's Windows Live account. Clicking through to Devices > super secret Samsung Window Phone 7 phone, "Find My Phone" functionality of the service will provide WinP7 users ability to see approximately where their phone is on a map which suggests a real-time fix rather than using phone's last GPS "check-in" location.
Users will also be able to ring their phone even if it's on silent and lock their device and provide a message for someone else to read on lock screen. Or, if things get drastic, users will be able to erase their phone. However with so much of a user's data on the phone also being stored in the cloud, erasing shouldn't be as terminal as suggested but is probably not recommended.