Neither, but he often draws comparisons to both. Analysts liken Fredette to Redick mainly because he's white and can shoot, and to Curry because he's undersized but can score. They differ in that Redick, although still slightly undersized at the 2, has more of an NBA shooting guard's body, and Curry--and this sounds racist, but it is true--possesses greater athleticism that allows him to create his own shot.
That being said, DBSF is as big a Jimmer Fredette fan as one can be of a player from the Mountain West Conference. His range is of Russian-Ballistic caliber, and he's a proven winner in the NCAA tourney and now on a top ten team (and number 2 in the RPI). But, there's something Fredette can take from Curry and Redick to succeed in the NBA.
While Curry is putting up impressive offensive statistics, his size--especially when playing alongside Monta Ellis--causes problems. (If you've never watched a Golden State basketball game, when they're on defense its a mix of an NBA All Star game and a pre-game shoot around. Luke Ridnour looks like Wilt Chamberlain.)
If Fredette wants to earn substantial time in the NBA he's going to have to figure out how to defend the likes of a Rondo, Westbrook . . . or Curry. Unlike the college game, the thing with the NBA is that if a guys is 6'3" or less, he's a phenomenal athlete--like could return punts for the Bengals even if he hadn't played football since Pop Warner. An undersized two-guard can't hope to match-up with Eddie House every night for 40 minutes and try to contain him on the perimeter.
Further, like Redick, Fredette will need to find a way to make his game fit the NBA. It took Redick about 4 seasons, but he is now an important contributor in an 8-man rotation on a Eastern Conference playoff team. Redick continues to rely on his jump shot and still cannot consistently create his own shot, but his defense has improved to the point where he could be a legitimate starting 2 guard on probably over half the teams in the NBA.
Of course, wanting to become a better defender and actually becoming a quality NBA defender are two different things, and defense--more so than offense--demands superior athleticism. While most analysts will likely continue to compare Fredette to white shooting guards and undersized-guards who've had to make the transition to the point, DBSF thinks if he can adapt his game to the NBA, Fredette could be anywhere from a Christ Whitney up to a Terry Porter. (And, if you think Whitney is an insult to such a prolific scorer, like Fredette, bear in mind that few players, especially 6'0" guards, make it 11 years in the NBA.)