I'm a firm believer that the level of support should depend upon the product being offered, at least within a particular platform. For example: expecting the latest video production or graphics design tools on a 5 year old system is probably a bit much. Expecting a program that displays book covers and formatted text on the screen, registers devices, and copies files to the device to support a 5 year old system is well within the bounds of reason (IMHO). That is especially true if they already support the platform since it basically compiling the source for two processors (Xcode should do that automatically) and being careful with the APIs used. Well, testing is another problem. But in cases like that they can say it needs 10.5 on Intel while having support for older systems compiled in. If things go wrong on those older systems and calls technical support they can say, 'it should work, but we only support 10.5 or later on Intel.'