Not so fast. Devean George exercised his contractual right to refuse the trade:
ESPN - Mavs forward George blocks trade of Kidd to Mavs - NBA
Jason Kidd remains a New Jersey Net for at least another day. He might not actually mind too much if that means he gets to play in the All-Star game. I'm sure something will be worked out within the next few days where an angry Mark Cuban either replaces George with some other player in the deal, or bribes George into accepting the trade.