That's politics working for you.
Basically both the ATC and the big iron drivers (because of spurious ACAS reports) wanted mode S to happen yesterday, everywhere. And initially that's what seemed to happen.
Until the GA community, the glider community, the hot ballooning community and anything else low-budget or low/no-power aviation started lobbying that things were going too fast, that low-power or low-budget mode S transponders were not available soon enough and so forth. Because of that, countries have delayed timetables and made exceptions in the form of airspace where mode S is not required yet. But those exceptions will not last forever. For the Netherlands, March 2010 seems to be the date where everything man-made that flies above 1200' has to have mode S.
My club has bitten the bullet and installed mode S in all planes this spring. We already did the IFR-capable planes about a year ago. If you haven't upgraded yet, flight planning will get more and more interesting. Especially now that flightplans without /S are being rejected in certain cases.