*****SPOILERS****
Mozzie's heart DID stop, but they were able to revive him and he survived. This all happens in the first minute of the episode.
There was some worry that Mozzie may not return to White Collar after he was shot in season two, episode nine "Point Blank." His heart stopped, but he survived. As of November 2012, Mozzie is still a character on the show.
Willie Garson
I know that someone saw Mozzie and Diana filming for season three, so it is most probable that he isn't dead. Also- Moz is a character that so many people love... The creators wouldn't want to disappoint audiences by killing Mozzie.
There are 14 episodes of White Collar in season 1.
16 white collar episodes season 2
The DVD for White Collar season 4 was released on October 8, 2013.
White Collar will return from the season four mid-season break on January 22, 2013.
White Collar season two started Tuesday July 13, 2010 at 9pm EST.
White Collar season four ended on March 5, 2013 with the episode titled "In the Wind."
White Collar will return for the second half of season four on January 22nd at 10pm EST on the USA Network.
According to some online sources, she is expected to reprise her role in season 4 of White Collar, possibly in the main cast.
Francie Swift played the role of Renee in season two, episode one "Withdrawal" on White Collar.