I think I'll get one of those OM13058s,
Yes, thats a really nice board.
For many cost sensitive applications it would be usedful to have just the chip like the LPC810. It costs only around 80 EuroCent.
Here I made an instruction guide on how make an LPC810 programmer with an Arduino Due:
http://www.hobby-roboter.de/forum/viewtopic.php?f=4&t=152&p=602#p602
I've been looking at the SAM D21 of late as well, great features but the registers are a real cluster f*ck.
Isn't it comming with the Arduino Zero?
http://arduino.cc/en/Main/ArduinoBoardZero
Probably they will provide the low level drivers ...