@bomber Did you find a way to use CC3000 as gateway?

I use a cheap Chinese 5100 module together with the MQTT gateway and it is warm but have not measured any actual temperature. Works 24 hours a day (now for a couple of months). Most problems have been due to the MQTT code implementation itself . But for most "simple" sensors it runs OK with Openhab.

http://forum.mysensors.org/topic/802/mqtt-and-batterylevel/2

And be aware of this thread where the ENC module is hanging after a while.. http://forum.mysensors.org/topic/536/problems-with-enc28j60-losing-connection-freezing-using-uipethernet-or-ethershield-read-this