The Surface RT has been a total disaster for Microsoft.
In fact they are being sued by investors who claim they were lied to about how well the RT was selling. See below (or search for "Surface RT disaster").
http://www.computerworld.com/s/article/9241606/Lawyers_sue_Microsoft_over_Surface_RT_unmitigated_disaster_
They are already cutting the price of the RT, and could well scrap it altogether and perhaps come back into the market at a later date with a "new" tablet.
I would not buy a Surface RT as I think in its current state it is a "dead end".
ps. Don't confuse the Surface RT with the Surface Pro, which runs a "proper" version of windows 8.
The RT only runs the "Run Time" version of Windows so you cant run "proper" Windows applications on it.