Discovered this one with one of my clients today.
Error Message: This view cannot be displayed because the number of lookup and workflow status columns it contains exceeds the threshold (8) enforced by the administrator.
Cause: SharePoint 2010 lists limit the number of fields that can be displayed in a list view. In this case, it was a 2007 list that was upgraded to 2010. The list worked just fine in 2007, but failed to render with this error in 2010. It turned out the list view contained 100+ fields. The 2010 limit is 80.
Workaround: Split the view into two views, the first view containing the core data and the first half of the extra fields and the second view containing the core data and the rest of the extra fields.