To take it further - I think he has plus defensive ability, but like many agressive young players, tends to gamble and not pay strict attention to the probabilities on a play or to adequately study his particular match up in order to learn the best defensive strategy for that particular player - this is a common flaw for many young players and we've seen it with a number of our own, including Perk, TA, and Rondo.
I don't think he'll ever be a good enough ball-handler to create iso - but his speed, explosiveness, and length should enable him to attack off screens and spot-up, taking advantage of defenders recovering or generally out of position on him.
He's improved his shooting substantially over the court of the summer and this season, including his FT accuracy, which was a must.
His ability to read the court and make plays for others is excellent - i'd equate it to Delonte West in terms of him being a 2-guard that can find cutters and kick-out options when he gets himself in trouble - also very adept at dump-off/drop-off passes to bigs when he draws defensive attention from help defenders.
I am sure he'll get the opportunity to spend the summer and TC showing he has learned enough to challenge for minutes - him and TA and Pruitt are all in a mix for minutes at the end of the depth chart.
If Giddens can get a handle on his ADD and assert himself as he has at the D-league level he can make a contribution to this club - but he's got to act like he belongs - something he didnt' do the first time around.