This could shave off some time in generating SQL Merge statement by hand. This helpful stored proc. will auto generate your merge statement on tables that use Type 0,1, and 2 SCD. The dim table just needs to be setup to use extended properties.
He uses the schema dim and etl to represent the dimension table and staging table, respectfully. The field IsRowCurrent is used to represent the current updated row.
An example of the extended properties being set through sql statement:
An example of printing the script: