I just found this campaign on kickstarter and found it very interesting:
basically it's a Atmel SAMD21 (cortex M0+) combined with a ESP8266EX WiFi-module,
realized on a very small form-factor (1,05inch x 0,73inch) [26,5 x 18,5 mm]
https://www.kickstarter.com/projects/krom/wino-board-the-tiny-10-arduino-with-wifi
it's somehow Arduino Zero compatible,
though it uses a smaller processor of the same family SAMD21E17 (128kB Flash / 16kB RAM / 48 MHz)
(it's meant to be programmed with the arduino ide 1.6.5+)
http://www.wino-board.com/index.php/en/wino-board/technical
I think the advantages are obvious:
- really very small
- it's cheap
- Arduino software compatible
- Arduino hardware compatible (with additional programming board)
- integrated Wifi & antenna
some disadvantages are:
- no integrated USB port (need a small add-on board for that)
- no 0.1" [2.54mm] breadboard-friendly header (it's 2.0mm instead)
what do you think of it ?
(I'm not related/associated in any way with the campaign owner...)