NUCs based on Broadwell won’t arrive until end of the year.

The two NUCs aimed at the consumer market would include a Broadwell CPU, integrated graphics, and offer support for USB 3.0, an M.2 SSD, a consumer IR sensor, and replaceable lids for both wireless charging and near-field communication (NFC).

Note the differences in the two depicted M.2 SSDs.  The M.2 connector can have different keying notches denoting various uses of M.2 modules. I am planing my next NUC build and will keep a close eye on Intel's compatibility list.

http://www.amazon.com/Intel-0-85-Inch-Solid-State-SSDSCKGW080A401/dp/B00ECAOZP0/ref=sr_1_28?s=electronics&ie=UTF8&qid=1393075694&sr=1-28&keywords=M.2+SSD

http://www.custompcreview.com/news/samsung-mass-producing-xp941-m-2-ssd-boasting-1400mbs-sequential-reads/18176/

http://mobile.extremetech.com/computing/216184-intels-nuc-roadmap-broadwell-coming-but-not-until-the-end-of-the-year

http://en.wikipedia.org/wiki/M.2