It would be great if I could do a true join (left / right / inner) on data from different sources (i.e. Excel / SQL, SQL from different servers, etc.). This would eliminate the need to create a data warehouse for certain reporting needs. You could extend the join table dialog box below to add a column for data source. Or you could create a dialog that would join data sources into a single extract file. Data blending just doesn't cut it when you need to aggregate.