Microsoft has committed to supporting the new Surface RT tablet for over four years, until April 2017. While this might sound generous, it’s actually less than half the usual product lifecycle of 10 years, because it’s considered a consumer product rather than a business product. This means that Surface RT will only get mainstream support – extended support is out.
Microsoft will support the Surface RT only in the “Mainstream” support phase, presumably because it’s considered a consumer product. The company typically supports consumer-grade software only during that five-year period; all business software, as well as some titles that are designed for consumers, such as Office Home and Student 2010, receive another five-year stretch, called “Extended” support, for a total of 10 years.