We've come to love Intel's Wireless Display (WiDi). It just too dang convenient. Forget about HDMI cables. You just need a WiDi adapter and you can mirror your computer's display onto your HDTV. Better yet, Intel has solved most of the original restrictions, as you can now play protected video content and it supports 1080p. (For more about WiDi, read Forget HDMI. Intel's WiDi Makes It Easy.)
According to some vendors at MWC though, WiDi isn't exactly power efficient feature, which is why WiFi Alliance has stepped in with its proposed 802.11-based wireless display standard (WFD). Presumably this is a better suited to smartphones and tablets. In theory, this overcomes many of the limitations with DLNA because you're mirroring the display. This means anything you see on the smartphone/tablet gets output. With DLNA, the codecs have to be just right and you need a compatible display. Plus, you can only play videos, music, and pictures. It's a far cry from plopping down on the couch and playing Angry Birds or Sonic the Hedgehog 4: Episode II using your smartphone as a controller in combination with your 55" HDTV.
We saw a prototype adapter by Cavium, and it's really small -- about the size of 10 credit cards stacked together. This makes it even more attractive than WiDi, because the Netgear PUSH2TV adapter is almost the size of a set top box. We're thinking that WFD might even have applications as a replacement for portable media players devices like those from Western Digital. If you're a traveler who wants to watch movies at your hotel, now you just have to carry around a small adapter and load all of your movies onto your smartphone/tablet.
At the present time, the technology is still in its infancy. The final standard should be worked out before the summer, and we hope to see devices with WFD by the year's end. To be clear, the demo previewed here at MWC is not exactly what will be shipping, as it relies on a frame based buffer to stream images. This creates high lag in several situations, well beyond the 200 ms threshold. The final version will use stripping, potentially reducing lag to under 100 ms, because this would only update portions of the screen which have undergone a change. In theory, this opens the door to smooth playback of fast paced movies and games that require quick reactions.