Uh. Was Engadget under the impression that it would be hard for someone physical access to your logged-in unlocked machine to get your password anyways?
I see the bug here and all, but it's not like any other non-Keychain-integrated app is better. Don't let people you don't trust use your computer.
Usually you're not allowed to change a password without showing again, even if you're logged on, that you know the current one.
Like I said, I get the bug. But it's not like Mac apps do that good of a job protecting secrets outside Facetime.