Will SSIS 2012 work with SQL Server 2008R2 (not integrated)
There will be no issues as SSIS 2012 will work with previous versions of SQL Server. I recently upgraded from 2008R2 to 2012 with 45 SSIS packages and all are working fine. As Always Test all your packages before hand on 2012. 

from this link : 

As you may already know, the SQL Native Client OLE DB provider is being deprecated. This doesn't affect other OLE DB providers or the OLE DB API. Also, the SSIS OLE DB components are not being deprecated.
In SQL Server 2012 SSIS, you can continue to use OLE DB connections and will need to for components such as the Lookup transformation and the Slowly Changing Dimension transformation that require OLE DB. In the post-Denali release, you’ll be able to upgrade and continue to operate these packages without needing to do additional work to explicitly remove OLE DB from the packages.