The set I saw employed a slick all-new interface that was able to browse to video, audio, and still picture files stored on the PC and play them back on the TV. Any PC on the network can deliver content to the television and even stream Windows Media 9.0 high-def files. The company stipulated support for just about every file format except for secure AAC (that is, songs purchased from the iTunes Music Store). The system will also have the MCE-like ability to get "push" media center content and to download content over the Web.
HP also mentioned the possibility of a built-in DVR, as well as the option to connect additional storage (USB or network-attached hard drives), but wasn't clear on details. I'm guessing that if HP goes DVR, it will use the subscription-based EPG found on Media Center PCs and devices such as LG's new LG LRM-519 recorder. Although HP only talked about networked LCD TVs in its demo, its press release left open the possibility of seeing the system in other types of TVs, including its new DLP-based microdisplays and plasmas. More-specific timing and pricing for HP's networked TV's was left unspecified.