From the WiFi FAQ doc, it's mentioned that currently the SDK supports MCUs from ST, Atmel and Freescale but that the support for additional vendors is in progress. Is there any plan to support Cortex-M3 MCUs from NXP? Or would it be possible to take the current SDK and port the WiFi stack to run on NXP devices (re-map the peripherals connections or simply call the WiFi related APIs in a transparent mode)? Or any other hint to use an SN8000 from Murata and the WiFi stack embedded in an NXP MCU?
Yes it is possible to update the SDK to support NXP Cortex-M3 MCU. You may take the ST or Atmel as a reference and update the SDK to include NXP.
SN8000 from Murata will give you a definite head start, they provide BCM43362 in a nice package, to integrate WiFi to NXP MCU.