Long-term, as in after the K66 board, I very likely may make a Teensy using one of those chips. I've been talking with NXP about future versions of that chip, but any info that's not yet on their website is covered by a NDA, so I really can't say anything more at this time.
In the nearer term, I'm hoping to see a shield (made by a third party, not PJRC) with one of the mature Nordic chips and Lipo battery management....