Freescale Kinetis KW platforms for 2.4GHz natively support Thread.
Kinetis KW2x wireless MCUs running the Thread protocol stack integrate a wireless IEEE 802.15.4 compliant transceiver with an ARM Cortex-M microcontroller architecture.
KW2x MCUs are available in several development or evaluation boards configurations such as TWR-KW2x or USB-KW24D512 dongle.