This is an interesting new device that I just read about last night in the latest CPU Magazine.
It sits on top of your TV and uses IR emitters to control your cable or satellite box so that it can change the channel. Then it streams the video over the network to remote computers running their Windows SlingPlayer software which receives the video streams and allows remote channel changes via an onscreen virtual remote control.
This means for example that I could watch TV on my office computer, without having a tuner card, simply by streaming it over the LAN from the living room to the office computer. Or even better, I could open up some ports on my firewall and stream video over the Internet, say to my laptop in a hotel room that has broadband access.