A frequently seen question related to editing SSIS packages for 2012 is related to the SQL Server Data Tools (SSDT). SSDT is the successor to the former BIDS and to the former VSDB. However, even though Microsoft likes to think of SSDT as a single product rolling up the functionality of BIDS and VSDB, there is no single installer that will give you this functionality.
There are two installers for SSDT: the one found on SQL Server 2012 media and the one downloadable from the MSDN web site at http://msdn.microsoft.com/en-us/data/gg427686. The installer downloaded from the MSDN site contains the developer tools that allow developers to work offline on database projects and closely mimicks the Visual Studio Database Projects from VS 2010. It’s not quite on par: features such as data generation are absent. Some missing features have been implemented as Power Tools, which can be installed from the Visual Studio Extensions window.
The installer provided with the SQL 2012 media provides the functionality of the former BIDS: reporting services projects, integration services projects and analysis services projects. And while the developer tools are freely available to all SQL Server developer users (including older versions and SQL Azure), the DW/BI development tools are available to licensed users of SQL Server 2012 only. The SSDT included with SQL Server 2010 Expresss Edition with Advanced Tools is a limited version that only includes the reporting services designers.
Read more about SQL Server Data Tools in the SSDT FAQ. Jamie Thomson has also provided some commentary on this naming situation.
Sven Aelterman 
Update: With the General Availability release of SSDT (including BI) for VS 2015, this issue is now put to rest. The SSDT for Visual Studio 2015 now includes all tools including BI. Download from here: https://msdn.microsoft.com/en-us/library/mt204009.aspx