If you stay up-to-date with the upgrades you shouldn't have an issue. At some point Adobe may say to get PS CS5 you need PS CS3 or later, but the original license shouldn't matter since you've got an upgrade license for PS CS3. I had PS7, upgraded when I got my D200 to PS CS2. I then upgraded that to a flavor of Creative Suite CS3 on a fresh OS install and was only prompted for the PS CS2 upgrade key (I can now ditch my PS7 hopefully). If at the time CS4 comes out I only want to upgrade my PhotoShop component I may run into Candy's problem - she had the full Creative Suite 3 (which, depending on flavor, includes programs like Acrobat and Illustrator, etc.) which apparently didn't qualify her to upgrade just the Photoshop component (despite tech support's assurances that it would). Think of it like owning the Office 2003 suite and not being able to upgrade to just Word 2007 while leaving Excel and Outlook at 2003.