While Sony had surprised everyone by not only zonant games on PS3, unlike the PS2 or the PS1, it seems that this idea can be challenged in the near future.
Since the advent of the SDK 3.50, it is possible for official developers restrict their Playstation 3 games at a specific region. For information, be aware that verification of the region of the disk was in fact quietly implemented since the 3.30 firmware but was not yet usable by the studios.
Here are screenshots from a Playstation 3 when trying to launch a drive to a "bad area".
The following an audit of this same disc into console development.
If any games yet so far does this "feature", however it is likely that it will be in the coming months.
Main Source: Scoop - Les jeux Playstation 3 bientôt zonés !