When Microsoft stops supporting Windows XP in April it effectively kills one of the most widely used computer operating systems we've ever had. Without support, XP ceases to be a viable option - unpatched and open to exploitation.
The focus of most of the commentary on the end of XP is necessarily on the security of legacy systems - a focus all the more pointed when you remember that there's an enormous number of machines still running that operating system (including the majority of cash machines). However, over and above the security concerns, the death of XP highlights a broader issue. As we leave XP behind there will inevitably be other software that is left behind too. Over time some XP software will become as remote to us as Word Perfect running on MS-DOS is today.
The end of support for XP signals the beginning of a slow death for software that has never been upgraded for later versions of Windows and the orphaning of data and information saved by the users of those programs. That is more than a security problem. It's the latest illustration of the fragility of digital information.
It seems odd to think of XP as a legacy system when we can all remember using it until very recently, but no-one thought that Word Perfect would go away when it dominated word processing or that Microsoft would change the default file format in Office either. In this respect, the end of XP is just another example of the need for intervention to ensure the longevity of our digital memory (for more in this, have a look at the work of the Digital Preservation Coalition or Chris Prom's Practical E-Records site).
The end of support for XP will lead to security vulnerabilities. In time, it will leave data and information vulnerable too. For me, it's the opportunity for the loss of the memories and stories in that information that's potentially apocalyptic; the longer-term consequence of the end of manufacturer support for any digital product.