Finally. After years of creating new workflows, running a test, only to have the CIO come into me and say "Hmm Brad I’ve received 200 emails in the last minute asking me to approve this task – could you look into it please?".
It appears that Microsoft have finally changed the logic so that an "On Change" workflow event cannot trigger itself by making changes to the current list item. This means that there’s a lot less test logic and column value validation that needs to go into a workflow, reducing the overall size and complexity of the workflow.
It’s in Service Pack 2’s updates – get it while it’s hot! http://blogs.msdn.com/sharepointdesigner/archive/2009/07/13/service-pack-2-prevents-an-on-change-workflow-from-starting-itself.aspx