Another aspect of its January growth might be that the 'Windows XP Mode' is available for Windows 7 -- you can have a complete Windows XP running within a virtual machine. A couple quick downloads and installs from Microsoft's site and you too can be running Windows XP within Windows 7.
I've got to disagree with you here...
Microsoft created its own problems with XP but that was because it didn't have the good sense to treat XP SP2 as a NEW RELEASE, not a free upgrade. Windows XP was released in 2001 and by 2007 it was time to retire it.
Windows Vista suffered from all of the same problems that Windows 2000 did:
- A NEW untested kernel -- new APIs which most ISVs simply ignored
- Sluggish performance -- reliability was more important than performance
- Excessively slow adoption rates
- OEMs who were uninterested in updating their drivers
- As demonstrated by all modern Windows applications, properly written XP code worked fine under Vista -- but in 2006, many, many XP titles were not written to Microsoft APIs and Microsoft got blamed for this
- To make matters worse, Microsoft set unrealistic expectations for Window Vista (actually Windows 7 runs better with 512MB of RAM than Vista did. (In fact, it runs better than XP does with 512MB of RAM)
- Like Windows 7, Vista needs 2GB of RAM to run well. XP-SP3 needs 1GB to run well
There is no doubt that Microsoft screwed up the Vista launch in any ways but Microsoft has since extended XP support twice. By the spring of 2014, when support ends, Windows XP will be a 13-year-old operating system. Frankly, I don't believe there is a netbook maker still shipping their devices with XP (at least not outside the third world).
When Windows 7 shipped in 2009, responsible IT departments had already begun evaluating Windows VISTA and began in earnest to evaluate Windows 7 to migrate to it. They will have had SEVEN YEARS (from 2007, when Vista shipped -- introducing the NT 6.x kernel -- to evaluated the next generation Windows operating system. That is enough time for any RESPONSIBLE IT professional so NO, I DO NOT THINK formal support should be extended YET AGAIN!
You've quoted the study that says that XP usage is up (by a VERY SMALL margin). I would bet that most of that 'increased usage of Windows XP' is from users still running on hardware from 2000 or earlier who are moving from Windows 95/98/se/Me who simply have no other choice because XP is the only OS left which will run on such lame hardware.
Should Microsoft be expected to support XP as long as there is a living soul who still uses it? (After all, lack of OEM hardware support left Vista looking at lot worse than it really was.)
Every OEM must decide what it can and cannot afford to do to support legacy customers. For instance, it would be less expensive to buy a new computer than to repair a computer built in 2000. Why put a lame 2001 operating system on it? That's just foolishness.