Before "Surface" referred to a line of tablets, it was the name of Microsoft's massively multitouch platform, used on the $8,400 Samsung SUR40 LCD table. Microsoft has now acknowledged this: a small note at the bottom of the Surface page reads "Looking for the Samsung SUR40 with Microsoft Pixelsense? Visit www.pixelsense.com." PixelSense was always the name of Microsoft's optical sensor for the SUR40, but now the company has removed the Surface branding altogether, even if the product page URL for PixelSense still reads "whatissurface.aspx."
Table-based Surface has been around since 2008, but at $12,500 its first hardware never saw wide adoption. Even the cheaper SUR40 is a bit of a white elephant. From what we've seen so far, the new Surface tablets don't share anything but touch capabilities with the original, so we're not sure yet if there's supposed to be a link between them. As some have noted, it could have been a way to develop branding without creating new pages that would be seen by prying eyes, or Microsoft could simply have decided it was too good a name to leave on a product far fewer people will ever use.