First of all, the low cost board is coming first, based on a Kinetis L-series chip. I know many of you want higher performance hardware, and that will happen, but I feel it's important to get a solid product out that really allows good 32 bit Arduino compatibility at approx $12 retail.
Teensy++ 3.1 will definitely not be released this year. The simple truth is I've spent most of this year on software. Hopefully a lot of good has come from all that effort, but it has pushed back plans for new hardware.
Until recently, I had planned on using the K22 chip. The K22 very well may still be used. In fact, I have a (not yet working) K22-based prototype on my desk right now.
However, I'm seriously considering delaying Teensy++ 3.x, for a new chip Freescale will be releasing next year. Obviously I can't talk about anything that's under NDA. But I can tell you I have only minimal technical info (not a datasheet or reference manual), but what info I do have says it will be very well worth the wait!
Freescale and ARM have already made press releases about Cortex-M7 coming soon. So far, I don't have pretty much any technical info about it, other than what's publicly available. But it certainly looks like it's going to be awesome... and perhaps worth delaying a Teensy++ 3.x board?