The tables will merge, but the views, sprocs, and functions will be overwritten.  The DDT puts an extended property on the sprocs, functions, and views that it deployed, so the DDT knows it can delete them.  If you remove the extended property (called "DDT_Priority"), then the DDT will leave the old objects alone, assuming that an end-user added them to the database.  However, when you go back to run the old DDT package, you'll need to swap over the DDT_Priority objects to the objects you want to overwrite.  It can be done, but there would be some scripting involved to mark/unmark the objects you want to replace.

If I have 7 tables, 2 views and some stored procedures and a few functions. Iwant to add these to an existing database with different table names,different view names and different procedure names, different function names. Will the DDT package leavethe existing tables, views and procedures not defined in the package alone in the existing database? Orwill it delete them? If the default is to delete them, how do I change the default?