Summary
You have several options available for migrating to Integration Services. The Upgrade Advisor tells you what to expect when you migrate, the Migration Wizard gets you started on migrating packages, and the Execute DTS 2000 Packages Task allows you to embed DTS packages into Integration Services packages. You can choose to keep all your DTS packages and run side by side with Integration Services while slowly migrating packages at your leisure, or you can migrate all your packages at once.
For more information, see the MSDN article "Migrating Data Transformation Services Packages" on MSDN at http://msdn2.microsoft.com/ and search for "Migrating Data Transformation Services Packages."