As previously posted, Lion will be dropping support for Rosetta. This means that older applications written specifically for PowerPC based Macs won’t run under Lion.

This site provides a list of all still commonly used apps that require Rosetta. Highlights are: Quicken (all versions), Retrospect 6, Palm Desktop (all versions), Now Contact (all versions), AppleWorks (all versions), Adobe Creative Suite CS1/CS2, QuarkXPress 6.5 and earlier, Microsoft Office 2004 and earlier, Toast 6 and earlier, and FileMaker 7 and earlier.