I can't imagine them needing to take a loss on sales of Surface RT. They already gave out tablets at the developers conference. Unlike Xbox, where they did take a loss for every sale, they are not looking to become #1 or #2 in the hardware game, nor will they make up for that lost revenue in sales of apps, as they did with games for the xbox. The Surface devices were/are catalysts for the market. Chances are MS will not make a living from these hardware devices..... In my opinion, if you want to experience RT, you may be able to find a refurb Dell or ASUS for 299 or so.
I just don't see the advantage for MS to "invest" (lose) 1.5 mil in RT which may or may not exist in a year.