Judging by his various combine statistics, he looks like a legitimate NFL prospect, although not an overwhelming one: Among college running backs measured, he was tied for third in bench press repetitions, fifth in vertical leap, sixth in shuttle, seventh in cones. His time in the 40 yard dash of 4.50 seconds was quite good for a 231 pound back, but there were about 10 guys faster. The fastest in the CBS Sports database was C.J. Spiller of Clemson at 4.27 and second were Ben Tate of Auburn and Jahvid Best of Cal at 4.34.
Gerhart's Wonderlic score of 30 (about a 118 IQ) was the best of the running backs. He was valedictorian of a working class / exurban high school, so he's a solid all-arounder.
He's being talked up as a second round or third round pick, with lots of NFL executives saying that they'd play him as the featured back rather than as the fullback (blocker, where white runners are usually stockpiled).
If I were him, I'd still be tempted by baseball. The Dodgers have a 230 pound centerfielder in Matt Kemp, and Gerhart is about as big and fast. As a hitter and fielder, Kemp was a Project for a long time, but now he's dating Rhianna because he's 230 pounds and fast enough to play centerfield. Gerhart hasn't shown in college baseball that he could hit major league pitching, but if he ever got the hang of it, it's a sweet life compared to getting mauled by NFL defenses.