Epson provides rebates on most of their photo printers almost monthly and the timeframe manufacturer's are going to launch a new version is around 5-6 years (average from what I can tell). I've personally seen 3 versions of Epson/Canon while at this company for just over 8 years. (Epson's x800/x880, x890/x900/P); (Canon's x300, x400, Pro).
The P5000 was launched about a year after the P series started shipping which replaced the 4900.
So, it may be a few more years until the manufacturer(s) provide a statement about a new version/series in the works.