Well, Deron Williams tweeted it himself. He is staying with the Nets.
Williams is going to sign a five-year, $100 million deal on July 11th, the date teams can sign free agents and make team trades official. Brooklyn was able to agree to an extension with Gerald Wallace, trade for Joe Johnson, agree to terms with Mirza Teletović, and acquire Reggie Evans. It has been a very busy few days for GM Billy King and his staff but this was a very successful offseason for the Nets.
With Deron Williams, they have their all-star point guard that can play alongside recently acquired 2-guard Joe Johnson and All-Star small forward Wallace. If Teletović indeed gets the midlevel, I can also see him start beside those three guys. I'll assume Brook Lopez starts at the center spot for them. If they somehow get Dwight Howard, what a starting line-up that would be for them... but Williams, Johnson, Wallace, Teletović, and Lopez is a darn good line-up as is.
Now Dallas, who had been angling to take Deron Williams this summer, have to think of a Plan B. Brooklyn is getting some squad this coming fall.