There are tens of thousands of medical instruments that still run XP. This means in a few weeks, they will no longer be considered HIPAA compliant and many medical facilities will not allow these devices to be used. Particularly the facilities getting federal reimbusements for medicare and medicaid patients. In many cases there are no upgrades available for these systems due to the way the code is written for a particular OS version. So they effectively become junk and medical facilities will be forced to spend big bucks to replace the equipment, if they can. There was an effort started by some medical groups to get a ruling on HIPAA restrictions until this gets sorted out, but I never heard more about it.
There are also voting machines, drive through restaurant displays, airport flight arrival/departure displays, etc. which use Windows XP.
There are different versions, however of XP. Microsoft has indicated they are dropping support for Windows XP Home and Windows XP Professional, which were intended for consumer and business desktop systems.
There is another version, Windows XP Embedded, which is used for more streamlined functions. I haven’t heard anything about discontinuing support for the XP Embedded product and I believe it is licensed by device manufacturers with support for their products.
I’ve seen Windows XP Embedded in the voting machines first rolled out in Fairfax County, VA and in digital signage control units, so I believe it is likely still a viable product.