That is a mighty tough question.
Jones, on some replays I have seen, is deceptively fast. Surprisingly, he is beating some corners with good speed deep. He is also showing some marginal Yards After Catch ability. The biggest thing against him is his consistency (even today he dropped two catches he should have made even though they were tough catches). It's hard not to fall in love with Jones potential when you see some of the things he does on film, but his inconsistency is a glaring weakness.
Driver is a stud. Old + reliable. He still has something left.
My first choice would be to keep both. If forced to chose though, I'd keep Jones. He's young and very talented - if he ever puts it all together he'll be a terrific weapon. There is no way we release Driver though, so I hope we can somehow resign Jones this off-season.
The NFL: Where Greg Jennings Happens.