Nokia has developed a potential successor to Bluetooth dubbed Wibree. Separating this technology from other potential, but more developed technologies (ZigBee) is its interoperability with existing Bluetooth radios, making cheap dual-mode devices a possibility.
While Bluetooth's power requirements are far less than other wireless protocols such as WiFi/802.11, some deem it still too high for some applications. According to MacWorld(Update: MacWorld was incorrect), the technology is capable of delivering 10 Mbps data transfers at up to 10 meters, however this may be in doubt as the technology's website cites "physical layer bit rate of 1 Mbps" (at up to 10 meters).
Apple currently uses Bluetooth for communication with its wireless keyboard and wireless Mighty Mouse, as well as communication with mobile phones via iSync.
Update: In addition to confirming the speed of Wibree as 1 Mbps, DailyTech posts some communication with the Bluetooth SIG on the subject:
It's important to note that this isnt an alternative for the majority of Bluetooth use cases that include the voice, printing, transfer and music scenarios. As the Nokia release points out, they are focused on sensor applications like the watch. However, like most technologies there is some overlap such as the mention of HID devices in the announcement. There are talks between the Bluetooth SIG and Nokia regarding the future of Wibree but at this point there is nothing concrete to say publicly.
Ultra low power Bluetooth technology is definitely part of our roadmap and the Bluetooth SIG is evaluating Wibree for possible inclusion into the SIG. Just like we are working with the WiMedia Alliance to combine Bluetooth and Ultra Wideband technologies and create a high speed Bluetooth channel, we will work to do the same at the ultra low power level.