While Gardner's hitting prowess is a major topic of debate amongst prospect watchers, there is no arguing his plate discipline and patience. His .412 OBP this year is a testament to his ability to work counts, find a pitch to hit or take his walks. Essentially, Gardner can do whatever it takes to get on base - a great sign from a potential leadoff batter.
Where Gardner's power projects in the majors is tough to say. Most say he has gap power, but I would call it more of gap+ power in that he can turn around on an inside fastball with more conviction than most might think. That said, he won't be putting balls over the right field short porch with regularity like, say, Johnny Damon can.
Gardner is not as polished an outfielder as say Aaron Rowand, but he has that same tenacity and gritty approach to the game. It comes out most clearly in his fielding. You won't see any Bobby Abreu type plays at the warning track - in other words, if making a catch in centerfield means cracking his head into a fence [like Rowand], there will be no hesitation. As is the case with his baserunning, Gardner's speed allows him to get to balls that other fielders cannot. He takes good routes to flyballs in the gap, but his instincts are not elite.
Gardner's arm is not a cannon in center, and is probably just about average in left tonight, but he has a good enough arm to play in the middle of the outfield and is very accurate as well. There will be no confusing Gardner with Melky in that regard, so that will be something to keep an eye on should Gardner ever supplant Cabrera.
Here's a bit on Gardner's 2007 accolades taken from MinorLeagueBaseball.com:
Over the last two seasons, [Gardner] has successfully stolen a base in 83.6 percent of his tries (97-for-116)...led all Yankees Minor Leaguers in stolen bases and tied for the Thunder team lead with five triples...successfully stole a base in 21-of-24 attempts with Scranton/WB...That two season stolen base percentage of 83.6 is an excellent indicator of Gardner's breakaway speed and great instincts in base thievery.
following the season, was named to the 2007 Arizona Fall League Top Prospects Team after hitting safely in 24-of-26 contests with the Peoria Javelinas...led the AFL in stolen bases (16) and runs scored (27) while ranking second in hits (37), tying for third in walks (17), and placing fourth in on-base percentage (.433) and fifth in batting average (.343).