Elgato Ships HDHomeRun For Wireless HDTV Watching On The Mac
One person can watch and record TV on a Mac, and at the same time a second person can watch and record a different channel on a PC. HDHomeRun connects to your existing TV antenna or cable TV outlet, and to your router via Ethernet. This allows the device to remain concealed in a discreet location away from your computers. Once connected to your Wi-Fi network, users can watch live TV wirelessly on a portable computer or iPad, anywhere inside the house.

HDHomeRun comes with EyeTV 3, the a software program for Mac that enables users to watch, pause, and rewind live TV on the computer. From there, they can search the Program Guide, record TV shows, and export recordings to iTunes automatically for playback on an iPhone or iPad. HDHomeRun is compatible for use on a PC; it works with Windows 7 Media Center, if you should choose. Elgato’s HDHomeRun solution paired with the EyeTV app enables streaming of live and recorded TV to an iPhone, iPod, and iPad via 3G. However, this is only available when using a Mac and is not available for PC.
It's currently on sale for $179.95, for those interested in such a thing.