Integration Services 2012 new development features

Project Connection Managers

This release allows you to create connection managers at the project level that can shared by multiple packages in the project. The connection manager you create at the project level is automatically visible in the Connection Managers tab of the SSIS Designer window for all packages. For details, see Add, Delete, or Share a Connection Manager in a Package.

Offline Connection Managers

Integration Services now validates all connections before validating all of the data flow components when a package is opened and sets any connections that are slow or unavailable to work offline. This helps to reduce the delay in validating the package data flow. After a package is opened, you can also turn off a connection by right-clicking the connection manager in the Connection Managers area and then clicking Work Offline. This can speed up operations in the SSIS Designer.
For more information, see Troubleshooting Tools for Package Development.

Flat File Connection Manager Changes

The Flat File connection manager now supports parsing files with embedded qualifiers. The connection manager also by default always checks for row delimiters to enable the correct parsing of files with rows that are missing column fields
For more information, see Flat File Connection Manager.

Parameters

Integration Services (SSIS) parameters allow you to assign values to properties within packages at the time of package execution. You can create project parameters at the project level and package parameters at the package level. Project parameters are used to supply any external input the project receives to one or more packages in the project. Package parameters allow you to modify package execution without having to edit and redeploy the package. For more information, see Integration Services (SSIS) Parameters.

Execute Package Task and Parameters

In this release, you can configure the Execute Package task to to make values available to the child package by mapping variables or parameters to child package parameters. For more information, see the Passing Values to Child Packages section of Execute Package Task.

Comparing and Merging Packages

The structure of package .dtsx files has been modified to make it easier for you to compare packages. You can also more reliably merge packages that don’t contain conflicting changes or changes stored in binary format.
For more information, see SSIS Package Format.

Undo/Redo in SSIS Designer

You can undo and redo up to 20 actions in the SSIS Designer. For a package, undo/redo is available in the Control Flow, Data Flow, Event Handlers, and Parameters tabs, and in the Variables window. For a project, undo/redo is available in the Project Parameters window.
For details, see SSIS Designer.

Column Mapping

When an error occurs due to a column mapping problem in the data flow, such as missing columns, the error icon appears on the path or above the component if no path is connected. In addition, you can still edit the component when there is a mapping problem.
The SSIS Designer is now smarter about re-mapping columns when a new data source is connected. Columns are re-mapped based on their name and data type rather than by lineage ID.
You can more easily resolve issues with disconnected input paths and unmapped columns in an execution tree, by using the Resolve Column Reference Editor.

Script Task and Script Component

If you create a package by using SQL Server Data Tools - Business Intelligence for Visual Studio 2012 that includes a Script task or Script component, you can configure the script project to target the .NET Framework 4.5 class library. You set the Target framework property in Microsoft Visual Studio Tools for Applications (VSTA).You can install SQL Server Data Tools - Business Intelligence for Visual Studio 2012 side by side with SQL Server Data Tools (SSDT) that is included in SQL Server 2012.Script tasks and Script components that target the .NET Framework 4.5 class library, cannot be edited in SQL Server Data Tools (SSDT) that is included in SQL Server 2012. The workaround is to load the package in SQL Server Data Tools - Business Intelligence for Visual Studio 2012 and change the script project to target the .NET Framework 4.0 class library.
It is recommended that if you plan to edit the package in both SQL Server Data Tools - Business Intelligence for Visual Studio 2012 and SQL Server Data Tools (SSDT) that is included in SQL Server 2012, to configure the script project to target the .NET Framework 4.0 class library.

Reduced Memory Usage by the Merge and Merge Join Transformations

Microsoft has made the Integration Services Merge and Merge Join transformations more robust and reliable. This is achieved by reducing the risk that these components will consume excessive memory when the multiple inputs produce data at uneven rates. This improvement helps packages that use the Merge or Merge Join transformations to use memory more efficiently.
Microsoft has also provided new properties and methods for developers of custom data flow components to implement a similar solution in their own components. This improvement makes it more feasible to develop a robust custom data flow component that supports multiple inputs. For more information, see Developing Data Flow Components with Multiple Inputs.

source http://technet.microsoft.com/en-us/library/bb522534.aspx