Well, if you are going from SQL 2005 to 2008 you are going from a BIDS environment to a BIDS environment, so that should be much easier than if you were upgrading from DTS to SSIS. You should be able to save your SSIS/SSRS solutions in BIDS and bring them in as new solutions in 2008.
Have you researched BOL any?
Considerations for Upgrading Integration Services
Upgrade (Reporting Services)