Has anyone made a manifest for this so it can be set via MCX in Casper? JAMF still does not offer this as a template.

You could just create it manually with the above keys.

Domain: com.apple.loginwindow
Key name: TALLogoutSavesState
Key type: boolean

Set to false.
I have it set to "user level at next login only" so it only initially sets it off since 10.7.4 introduced the "set it and forget it"-ness of this setting.

I set up a new Managed Preference with the domain/key in the first post, and i'll report back as to how it works.

The reason I need to apply this setting is that our custom Registration Application reboots the machine upon completion, and re-launches itself when this setting is enabled, even though the plist it leaves behind tells it not to launch.