The Economist offers insightful business and mainstream technological details on ultrawideband (UWB): The article spells out how the technology works, who the players are, the current struggles in committees over standards, and which products will make it first to the market. I believe the piece downplays the significance of UWB's range versus the potential 802.11n standard.
UWB devices will certainly now make it to the market, but you have to wonder if there is a large enough class of equipment that needs high-bandwidth over very short distances when a competing standard might offer substantially longer ranges. Home-entertainment devices certainly apply, but what if you want to use UWB-equipped speakers in the kitchen and it's just a little too far from the media room? Frustration ensues. Or lower speeds.
Many of the folks in the UWB field note that UWB doesn't just stop working at greater distances, but it can't perform at anything like its real potential beyond about 10 meters in the standards that have been on the table to date.