While the Surface RT tablets are still working - and will continue to for as long as their hardware lasts, the fact is that the OS is being killed quicker than Microsoft can say "Zunepass". Microsoft was all geared up for universal apps that would work equally well on their Surface devices, Windows 10 desktop devices as well as their Windows 10 mobile devices. Microsoft just announced that they won't actually be supporting Windows RT after all. This is not surprising to me or Jason I'm sure, but it just shows how big of a mistake Windows RT was for the company.
Microsoft has said that after Update 3 is delivered to Windows RT users (primarily Surface 2 owners), the device will not support Universal apps. This means that if a developer takes advantage of the new functionality that the company is pushing heavily, that developer's app will not work on the company's aging tablet.