5miles -
The 'not very accurate' UK system you refer to is the envy of many of your european counterparts. Rather arrogant to use that term when you admit you're not very knowledgable in these matters. Maybe you should become a little more educated in the system before knocking it.
It's not exact, no system of this nature is in ATC, but it's very accurate based upon the information supplied within a flight plan. It's not a crystal ball !
Other ANSP's are looking at this system closely and I wouldn't be too surprised if some of your nearest neighbours find themselves with it sooner rather than later !!
To answer another of your thoughts - The CFMU system picks up live radar activations so regardless of pending EOBT, the system does know the flight is airborne and enroute centres will know to expect it. This will not be the case though for flights originating from the USA/ASIA etc.