TI's new wOne software can support simultaneous use of 802.11a, 802.11b, and 802.11g networks on a single chip: Other dual-band devices use multiple chips to support the different standards. TI claims that using a single chip will decrease the cost of products.
The catch is, when an access point with TI's chip is running two networks simultaneously, they both take a hit. Users will get around 10 Mbps on either an 802.11a or 802.11g network when running them at the same time. If that's what the manufacturer says, real life ought to produce even slower speeds.