I am thinking the Show has not even started yet and I am exhausted from the previews.
AbelCine and Vision Research announce PhantomFlex4K, http://blog.abelcine.com/2013/04/07/nab-2013-first-look-at-the-phantom-flex4k/ but the best part is Vision Research is showing footage here https://vimeo.com/63490371
BlackmagicDesign Announces 4K for $4k version of BMCC camera, 1080 Version for less than $1000, Details to come on their website http://www.blackmagicdesign.com/products/blackmagiccinemacamera/
Sony snuck a couple of camera updated one a 4K Sensor update to their DSLR Line, and a new lower profile 2K prosumer camera. Details to come.
Element Technica has been acquired by RED Digital Cinema http://elementtechnica.mybigcommerce.com, I am thinking this is one of the best announcements of the NABShow so far.
Lastly Avid announces Media Composer 7, it seems that some native codecs are supported, specifically the just released Sony XVAC codec for the F5 and F55 cameras.