Does the "Melk-Man" really deliver?

New York Yankees center fielder Melky Cabrera is one of the most interesting players on the team, in that he seems to always fly under the radar.  For one, the fans never seem to get on him when he goes into an extended slump, which he seems to be struggling with lately, despite a few clutch hits.  I find that quite interesting because he has basically taken over for one of the most loved center fielders of all time in Bernie Williams.  This is most likely attributed to the fact that the Yankees lineup is stacked with stars, but Melky still seems to never be talked about if he is slumping, or if he is doing great.  

 Melky is at a point in his young career where he is most likely about to go in one of two directions.  He could either completely explode, and have a great year, which he showed signs of in April.  Or, he could continue to be slightly above average and hit his usual .270.  Even if he did stay slightly above average offensively, he still fits in nicely in this Yankee lineup, especially when Posada returns.  Also, he has been very good in center field, which the Yankee's seem to be thrilled with.  But will be be around for years to come if he doesn't begin to break out offensively?  The answer is probably not.  Center field prospect Austin Jackson, who the Yankees scouted since twelve years old, is still grooming in the minor leagues.  The Yankees say he has tremendous speed, and has a swing that they have compared to Derek Jeter.  They say at about 20 years old, Jackson is already ahead of where Bernie Williams and Jeter were when they were his age.  

So does Melky have a future here in New York, or is he just filling in until Jackson is ready to take over?  I don't know for sure, but I think the "Melk-Man" should consider delivering at a faster pace.