Microsoft has not released any official sales number for either Surface device, but it is fair to assume they're selling moderately well. Bloomberg reported that 400,000 Surface Pros had sold, along with 1.1 million Surface RTs, a drop in the ocean compared to Apple's 7+ million iPad sales in the same period. Despite favourable reviews from technology websites, including Neowin, Microsoft may still be disappointed with the sales figures.
But they will not give up, according to CNET. Sources who are familiar with Microsoft's plans for the Surface RT insist that it is part of a longer strategy for Microsoft. With Windows Blue, some were predicting that Microsoft may kill off the RT in favour of the Pro, which is the more useful of the two tablets as it supports the millions and millions of Windows-based apps that require an Intel CPU. DigiTimes had previously reported that Microsoft were set to "merge" their Windows Blue technology with the RT; CNET says that's currently the case with Windows 8 (Note: DigiTimes have a very poor track record with rumours).
CNET's source told them that the two code bases - one for RT and one for Windows 8 on the Pro - are identical anyway. There is one Windows Store for both ARM processors (found in the Surface RT) and Intel x86 processors (found in the Pro and most laptops).
The source reiterated what Michael Angiulo, Microsoft's corporate VP for Planning and PC ecosystems, said in an interview with CNET on their long-term goals for the RT. In the interview, Angiulo said:
It was a ton of work for us, and we didn't do the work and endure the disruption for any reason other than the fact that there's a strategy there that just gets stronger over time.
In the interview, Angiulo made it clear that ARM processors are superior to Intel chips when the device is connected to a 3G/4G connection, i.e. in a tablet or smartphone.
DigiTimes reported that the RT's lack of compatibility with legacy Windows apps - both from Microsoft and third-party sources - had "seriously damaged demand" which may still be true. Samsung announced that their ARM-based Windows 8 tablet will not be available in the U.S, hinting at a serious problem for Microsoft.