The only thing that changed with the latest FCPX update is that a third party developer has offered software that can transfer project files from legacy Final Cut 7 to FCPX and another software app to go from X to 7.
Not sure what you mean by compatible but if the ability to move projects between the two different version of FCP is important then it might be worth testing this new software.
FCPX doesn't support SAN or shared workflows but that may change with future software updates.
I see where you were going now. Just sounded like you were kinda taking the bizarre stance that 10.0.3 didn't have any features worth mentioning except a 3rd party plugin. Since they discontinued Final Cut Server before X was even released, I doubt it will support it in particular.