From the tweets today:
"Aw, yeah! RT @Ronnie2K: HUGE next 3 weeks ahead. About to blow all #NBA2K13 fans minds like never before.#turnonhypemachine #yeahIsaidit"
NBA 2K12's first developer insite was August 12, the second Friday of August,and the sencond Friday of August is August 10.
I guess this is the tweet tells us, so let's looking forward to the day coming!