He's fast (4.32 in the 40). He can throw (he's not great, but he can). He was a pretty good running in college. He never worked out at wide receiver in college, but he gave it a try at one of the all-star games and didn't do bad for just a few days of coaching.
So basically he has the capability of doing it all which makes him the perfect OW.
Denard Robinson was a good quarterback in college. Not great--just good. Being a good in college rarely translates to being even average in the NFL let alone great. Robinson knew this and did the smart thing by telling scouts that he was open to playing whatever position the team wanted him to.
The Jags could use the help just about everywhere, but I hope they don't try him at offensive line. That might be kind of pushing it!