Too many "fuck fat joe" posts here, so I'll add my take on Piggy Bank...
I don't think Piggy Bank was really a diss record. Like it says above, just "harsh truths". Also 50 says at the end that he wants to see how they'll respond, then he'll release his reply (which I took as meaning a proper diss record).
Also in a battle it's about who gets the harshest, not who has more skills. So it
doesn't mean Nas or Jada are gonna win. I think 50 has a pretty good sense of humour so he may suprise a few people. And as always he will be spitting over hot beats.