It turns out that "SQL Server Data Tools - Business Intelligence for Visual Studio 2012 (SSDT-BI)" is a package that is separate from SSDT. It can be downloaded from here: http://www.microsoft.com/en-us/download/details.aspx?id=36843.
Installing SSDT-BI is fairly straightforward, except the following:
- It will launch the SQL Server installer. You will need to check the "SQL Server Data Tools - Business Intelligence" as an option.
- If you are running a 64 bit OS, you will need to select "create a new SQL instance". Otherwise you will get an "architecture mismatch" error, and the installation will fail. The installer will not actually create a new instance of SQL.