Well I for one am relieved, having just bought the PA1-X Pro, I feared I had bought too early (I really needed a new board urgently though).
I may be jumping the gun here, but if the following basic upgrades are true:
256 Meg Ram Sampling
Tilt Screen
Mp3 Dual player recorder
...then I don't feel the need to upgrade just yet!
The only idea I would love is the tilt screen.
The rest - well nice but hardly necessary.