Making software specifically for the G5... now that is a VERY STUPID IDEA!!
I will never accept that software applications written for specific chips should be designed to move hardware.
A much better idea would be to make software that works on as much hardware as possible... but take advantage of specific hardware WHERE IT MAKES SENSE.
Chopping off the current user base to support the G5 chip is the worst idea anyone can think of, particularly since Apple went to great lengths just to make the G5 remain compatible with software written for the G4 and G3 processors.
Time for a G5 only iApp