They were basically obsolete from the beginning: Massive plastic coffins that beamed media from your PC to your TV. That's it. For $400. And now they're returning to the abyss, where they belong.
Besides HP killing their Smart TVs and Connect Media receivers, Linksys's DMA2100 and DMA2100 are listed as "discontinued" at B&H, Niveus Media's Media Center Extender is delisted points out Engadget, along with Samsung's MediaLive Digital Media Adapter. Only Netgear's Digital Entertainer Elite appears to be holding strong.
Any company who proclaimed to be in the home entertainment or networking biz had one, and now they're all silently shrouding them in death ShamWows. To quote the Joker, "What happened?" Well, to start, they mostly sucked, really, really hard. HP's most recent box required a PC running in order to rent movies so it could authenticate your CinemaNow account. And just try scrolling through your catalog of 13,000 songs, on any of these things. We'll see you in 2020.
Even when they are decent, they perform almost the exact same function as an Xbox 360 or PS3—which are also actual gaming systems for the same, or even less money. Not to mention Boxee on Apple TV or super-powered Blu-ray players packed with Netflix that also slurp up audio and video. What doesn't stream audio and video? Dedicated streaming boxes are one-legged men in a ruthless cyborg world: Destined for slaughter.
Difficult, expensive and redundant, they lived on borrowed time. And now they're dead.