ARM is intensifying its attack on the 8-bit controller market with a new ultra-low power processor core, the Cortex-M0. At claimed 0.85 µW/MHz the power efficiency is comparable to controllers of the AVR or MSP430 families. The Cortex-M0 implements the Thumb-1 and a subset of the Thumb-2 instruction set, so the same level of support by open source tools can be expected as for the other ARM cores.
NXP, best known for its ARM7-based controller family LPC2000, has announced to become the first licensee for the Cortex-M0, though no specific products have been announced yet.
What about price/unit? much lower then cortex m3 or pic32 ?