This didn't work for me today. I d/l'd CS3 Pshop beta, installed it, and renamed the AMT/application.sif to application.sif_, but Photoshop CS3 will NOT RUN. They've apparently discovered this little workaround and put a stop to it with a simple dialog telling you that the license has been canelled for this product, and you must uninstall it and reinstall it to run the program. When you click OK, the program quits.
Photoshop beta works fine though if you rename application.sif back to its original name. But then you're stuck with your 30-day trial.
Might as well buy it now if you want it, but I'd wait for the release anyway. I typically like to stay legit with software vendors, particularly Adobe, who is the best developer out there for graphics software, and who doesn't pull a lot of the horrible fascist stunts like other companies, such as Quark ... and Adobe's upgrade policy is the most liberal I have ever encountered. I'd recommend supporting this company instead of trying to rip them off. But that's just my personal opinion.