We have been modifying some of the tools in the 10 version and Flow Direction with Sinks is one of them. You can still access the old version of the tool in the Arc Hydro Tools toolbox but it has been removed from the menu. The tutorial has not been updated for 10 yet. You can check the attached document that discusses the new workflows for terrain preprocessing with the new tools. Some of the new tools may be accessible from the toolbox only.Christine DartiguenaveEsri Water Resources Team