I tried to run some of our spread sheets and macros in the trial excel 2007 and I'm so disappointed!
Having distributed product and user manuals for stuff using lists, macros, toolbars and add-ins we are now faced with avoiding office 2007 all together or spending our funds and the customers time to retrain them to operate on the new platform for no additional functionality!! The product may have additional functionality (I haven't looked since we were overwhelmed by the amount of work) but its not needed for our customer base.