Third of August, or even sooner.
Link: http://wololo.net/2017/08/03/nintendo-switch-hackers-warn-updating-firmware-3-0-1/
At least thats when it was announced on wololo.
https://www.amazon.com/Nintendo-Switch-Gray-Joy-Con/dp/B01LTHP2ZK/ref=sr_1_3?s=videogames&ie=UTF8&qid=1503007990&sr=1-3&keywords=nintendo+switch
one left...