According to Adrian Wojnarowski of Yahoo! Sports:
Orlando has traded J.J Redick to the Bucks, league source tells Y!
— Adrian Wojnarowski (@WojYahooNBA) February 21, 2013
The deadline is 3 PM ET, so the teams are skating close to the deadline with getting it finalized, but the league usually will allow a few extra minutes for details to get sewn up.
Wojnarowski also tweeted that the Bucks sent out Beno Udrih, Tobias Harris, and Doron Lamb to Orlando in the deal. Ish Smith and Gustavo Ayon are coming to Milwaukee from the Magic.
Redick is an unrestricted free agent at the end of this season.
For a reaction to the implications of the trade, see here.
Updates coming shortly.