"Designed mainly for getting grandma and grandpa (GM+GP) online, WebTV never got much respect from early adopters who scoffed at the whole idea of surfing the Net on a TV screen, but it did get a lot of people online who couldn’t afford a proper PC (or who didn’t want to deal with one), with its subscriber rolls topping out around a million when Microsoft snapped it up in 1997 and renamed it MSN TV a few years later. Fast forward to 2004 and Microsoft’s new MSN TV2 Internet Player can still do dial-up, but they’ve added an Ethernet port and are positioning it as a way to get online for the 51% of Internet users who do have a broadband connection but don’t want to spring for a second PC just so they can check email and read websites. Better still, it can pull double duty as a wireless media adapter that can stream audio and video from the hard drive of your PC to your home entertainment setup."
I'm not sure that these "WebTV" are really sellable anymore, but I think Microsoft has finally created a unit that might be usable. With USB, support for broadband and WiFi (using USB WiFi adapter) and support for the latest WMV/WMA and other Microsoft standards. The only missing parts are support for bluetooth and flash memory readers. Don't look for a hard drive because this unit is running windows ce, so you'll need to stream your files from somewhere else.