Freescale has released fully integrated MC1322x ARM7 based Platform in a Package (PiP) RF transceiver for 802.15.4 wireless networks. MC1322x  has 128KB Flash, 96KB RAM, 80 KB ROM plus GPIO,ADC,UART,I2C,SPI and even keyboard interface click-here for more info. Looks like a very good solution for 802.15.4 based networks including ZigBee, 6LoWPAN, HART and ISA100+.

First poducts based on MC1322x are already showing up, for example this FreeStar Pro radio module from CEL.