From SQL Server 2005 Books Online, Configuring Integration Services in a Clustered Environment:

The Integration Services service is not a clustered or cluster-aware service, and does not support failover from one cluster node to another. Therefore, in a clustered environment, Integration Services should be installed and started as a stand-alone service on each node in the cluster.

Microsoft does not recommend that the Integration Services service be configured as a cluster resource.

That being said, if you decided to create a cluster resource for SSIS, you may experience issues trying to install SQL Server hotfixes. When installing a hotfix, the install may hang when it attempts to stop the msDTS service. After about 15 minutes, it will time out and fail.

 To avoid this issue, before running the hotfix install, take the SSIS cluster resource off-line. Do NOT take the SQL Server resource off-line because the hotfix will be unable to ascertain the state of SQL Server and will fail.