I'm not so sure that it is that easy to determine the success of DLNA at this point. A lot of the Comcast acquisition of Time-Warner is driven by positioning for a world where cable TV is shrinking and ISP business is growing. If people get their TV from a proprietary cable box it tends to drive them into a vertical and proprietary technology stack, but if it comes from a network connection then things are more complicated and there are more opportunities to put together interesting combinations. This is where DLNA can still shine, if it can put together a combination that normal people can accept and use.
Sometimes, standards efforts get overtaken by events? I would say that Chromecast allows people to transfer content from your tablet screen to your TV screen, no? From a USB port on the tablet, wirelessly to an HDMI port on the TV.
Or, you can always connect a wired HDMI interface from PC to TV. Many PCs have HDMI interfaces these days. That autoconfigures too. Or, RGB analog. Many flat panel TVs support that too, these days.