It wasnt too long ago that they dropped the prices of the 17 PBs, so I wouldnt expect anything dramatic. If anything, it will be in the $100 area, but personally, I wouldn't expect it, especially since they will probably sport an enhanced G4 (which will create enough excitement for them to justify the prices for a while longer). Heck, when they put G4s in the iBooks last year, they actually raised the prices by $100.
I ramble, but what I am getting at is that I would expect the prices to remain the same for the forseeable future.