Here’s a look at Find My Mac configured in iCloud on Mac OS X 10.7 Lion. It works just as you would expect it to with the Find My iPhone app on your iPhone, iPod touch, or iPad.
Only Guest users will have access to Safari which will aid you in the recovery, locking or wiping of your Mac.
iCloud Sync Settings for Mac OS X 10.7 Lion


Locate Your Mac On Your iPhone


Options You Have For Controlling Your Stolen Or Lost Mac Remotely

Mac OS X Lock Screen With Pin Prompt

What’s Missing
There isn’t a feature that allows you to activate your Mac’s built-in iSight camera. So you won’t be able to see an alleged notebook thief sleeping on his couch. Maybe Apple will add that feature sometime between now and the release of Lion and iCloud later this year.