Check this out: http://msdn.microsoft.com/en-us/library/ms345184.aspx
This may seem unrelated at 1st, but give it some thought from an architectural perspective.
If you have an SSIS parent server containing parent packages.
Then several Child SSIS Servers for both load balancing and possibly failover.
The architecture would also call for a seperate database server.
Each child SSIS server can contain every package. This way if a failure is reported back to the parent server it can try to run the same package on a different server.