Upgrade from 2005 and 2008 R2 to 2012 SP2

My project is getting ready to upgrade from SQL Server versions 2005 and 2008 R2 to SQL Server 2012.

Is there any known issues that we should look out for?

For SQL Server 2005, we are only running the Database Engine, Full text search and SQL Server Agent. 

For SQL Server 2008 R2 we are running Database Engine, Full Text Search, SQL Server Agent, Analysis Services, Reporting Services, and Integration Services.

DJ