Yes. 6LoWPAN is IPv6 over a Low power Wireless Personal Area Network, typically based on the IEEE 802.15.4 standard. This is essentially what IPSO promotes.
Others like Zigbee use similar physical layers but typically use their own higher layer protocols not IP.
Some IPSO folks may still use IPv4 but the trend is clearly to IPv6.
Amazing to think of how quickly this IoT will move forward. NEST and Fitbit, though technically may not be IoT, have opened my eyes as to how quickly and how useful IoT will come to be.