"Play To" is the ability to right-click a media file in Windows 7's Media Player and send it to any networked gadget appearing in the pop-up menu. It's sweet now, but it could be huge.
The key is that you have to have compatible networked "digital media renderers" at the receiving end. Right now, the list is verrrry short: Sonos is the poster child for the feature at this point, and when you right click a song and send it to the Sonos ZonePlayer in any room, it starts playing no problem. But Sonos is for music only and so is Roku's SoundBridge, which has a variation of the feature enabled on its latest firmware. Video is the holy grail, but for now, the only thing you can send video to is the Xbox 360—and then only when it's running Media Centre Extender.
This will change soon, when the DLNA rolls out its "Play To" certification as part of the 1.5 specification. The functionality will likely find its way into loads of media-rendering products: The PS3 is key, but ideally this will be in TVs, connected stereo systems, media adapters and digital picture frames too. Can you imagine how nice it would be if sending a photo to a frame was a right-click away, instead of some convoluted 12-step process requiring proprietary software and a steady easterly breeze?
In other words, though Play To is first coming to life as a Windows 7 attribute, it will hopefully not be just some Microsoft (TM) thing, but a platform that all computers and devices can get with, a whole-house "This just works" thing. Yes, I can see you naysayers wrinkling your noses already: It's a dream that potentially has nightmare written all over it. But at least with Windows 7 and supported devices, Microsoft is burning some midnight oil to make it work.
And the PC is potentially good for getting around kick-in-the-stomach file-format rejections we see in connected products: Windows 7 will automatically render files that it knows the networked device itself can't accept. For instance, a media player that doesn't like AAC will be delivered a more palatable WMA audio track in realtime. Microsoft even says conversion will work with video files—as in, flipping an XviD of The Big Lebowski into WMV as you're watching. It's early in the beta, so there's no telling how pleasant or painful that experience will be. Needless to say, it's not testable just yet.
The other reason the PC is so cool for this is that you can browse files that live somewhere else on your home network. When you find one, you right-click and send it to some other device, clear at the other end of your house. The computer isn't a media player at all anymore, but a big expensive universal remote that also does email.
The experience today isn't life changing, but I was able to play networked music on the Sonos, control its volume, build a playlist and skip around, all with no problem, and with no Sonos software installed. Play To isn't entirely compatible with official Sonos controllers yet (those show that the ZonePlayer is doing something, but won't name the track or show any metadata). It's possible that these issues will be solved by the time Windows 7 is released.
I mentioned that the Xbox 360 needs to run Windows Media Center Extender to use Play To. I think this is a design flaw. I hope that the developers will see fit to make Play To work with Xbox's native media players, because they're much better than the Extender in a lot of ways. In testing so far, we've been able to send WMV and certain AVI files over—even, as you can see in the image, while sending music to a different media player. Still, not all files work yet, not even all the ones supposedly supported. I chalk that up to the beta status, though, and I know Microsoft is doing some serious problem-solving in that area even now.
I don't want to sound like some hippie, but there's no telling what Play To could achieve if everyone—Mac and PC, PS3 and Xbox, and any digital media renderer, be it a Samsung Blu-ray player, a Philips photo frame or a Sony Bravia connected LCD—got on board. Here's to hoping, and to this first step looking none too shabby. [Windows 7 on Gizmodo]