For SSIS, there was definitely a change from 2008 to 2012. I upgraded my packages although I dont know if this was a requirement (dont know if they would not have run). you could have both SSIS 2008 and SSIS 2014 running side by side and migrate to SSIS 2014 on your own pace.

here is some more info on upgrading SSIS(https://msdn.microsoft.com/en-us/library/cc879336.aspx) and SSIS packages (https://msdn.microsoft.com/en-us/library/cc280546.aspx)