I have been beta testing Photoshop/Bridge CS4 over the last few months and I’m pleased to say there are some real improvements to the stability, speed and usability of the programs.
Most of the improvements benefit high end rather than production retouching (rotating canvas, content aware scale etc), I have used these tools for real retouching jobs and been suitably impressed.
On the downside metadata handling has not been improved (The same “Multiple values” bug when appending keywords and captions as per CS3) and there is still no central configuration system for all the varied settings.
As far as I can see all my client CS3 actions run without modification on CS4 – will check this when I recieve the retail code.
I will contine to support CS3 for the forseable future so dont feel you will be left behind if you don’t upgrade. Workflow and retouching workshops can be held with either CS3 or CS4.