Spun out

Microsoft has won a contract to provide software for 900,000 NHS computers. Apparently this is a money-saving deal as an open source solution couldn't possibly be cheaper than paying Microsoft licenses. But my issue with this contract (which the Beeb doesn't report) is that it's for nine years. So the government is committing our health service to using technology that it cannot possibly predict the worth of. To give you some examples: nine years ago Internet Explorer barely had a ten per cent share of the internet browser market, Netscape was by far the biggest thing; a new version of Windows was about to be released that would allow applications to truly run simultaneously (this had previously existed only on Macs); the .mp3 file format was not yet distributed; and no one had heard of Flash memory, central to the ubiquitous digital camera and mobile phones.
How can a contract that commits to such ridiculous unknowns possibly be momney-saving?