Sorry about the issue. We chose not to change the default direction logic used by ArcMap at 10 because it already had its own precedent but you can change the setting yourself:
ArcMap and ArcGlobe 9.2, 9.3, 9.3.1: Tools pulldown menu > Options dialog General tab
ArcMap 10: Customize pulldown menu > ArcMap Options dialog General tab
ArcGlobe 10: Customize pulldown menu > ArcGlobe Options dialog General tab
Starting at 9.3 in that same dialog you can also choose whether the zoom is centered on the middle of the display or on the current cursor location.
Well the work around this issue literally takes 5 secs, and since they have been using this schema since the beginning so many users are used to it. Changing the default now would be awkward for many of them, if you want it to be inverted change it yourself and consume 5 secs of your time.