Your life will be a lot easier than someone moving a custom app, that's for sure. Microsoft has migration tools for old versions of SQL Server to new. There's some complexity in that you have to "demote" the old version, say, SQL Server 2005, and "promote" the new version. This way your data all goes through the new version. That all involves deploying the new SQL Server, which migrates over your data and apps. The good news is it's all done inside SQL Server itself.