MSSQL 2008 vs. 2008 R2?

Hey guys,

I am currently using SQL Server 2008 Developer to build my .NET applications. Since I only use it for Win/Web apps is it worth upgrading to MSSQL 2008 R2? Meaning do they offer new features for developer, that would be worth upgrading, or is this more of a non-developer “update” rather then “upgrade”, which would be a whole new version (2005 vs. 2008).