According to AutomatedHome the third generation Z-Wave ZW0301 Single Chip is available in production. Its features include the ability to support battery-to-battery networks, lower power consumption, and full interoperability with previous Z-Wave products. Depending on the volume, the ZW0301 has 15 to 30 percent lower cost than the 200-series generation of Z-Wave chips. This means that dimmers, switches, sensors etc which are based on Z-Wave technology will be also cheaper and more efficient.
Taking in account of Z-Wave initiative to combine TCP/IP and Z-Wave I can guess that Z-Wave will be at least one of dominate wireless technologies in the home automation area.
P. S. You can buy Sylvania Z-Wave Deluxe Starter Kit, included one remote control and two #2000Z plug-in lamp modules, for $99.99. Good opportunity to start automation of your home with leading technology!