This article discusses Intel's belief that wireless networks in the home are inadequate for high definition television. The highly touted 802.11g, with a theoretical maximum bandwidth will only deliver about 22 megabits under the best of conditions in an in-home network, and performance could be much worse. In other words, it will barely handle a single channel of HD TV--as long as you or any one in the family is not doing anything else on the network.
Community wireless projects that rely entirely on WiFi are going to be similarly disappointed, as that bandwidth now has to be shared among several households. WiFi and its variants don't work well going through walls, and the wireless systems that experience poor reception because of interference operate much more slowly.
What does Intel recommend? The firm suggests wiring your house with Ethernet cable designed to support the very efficient Gigabit Ethernet standard (Cat 5e or Cat 6 cable, which is very inexpensive).