+1 for a repository of workflows and packages :-)
Unfortunately there is no such repository (...yet)
Find some samples available on different blogs:
www.vcoteam.info
www.vcoportal.de
http://mighty-virtualization.blogspot.de/
orchestrate-this.blogspot.com
Also don't forget to see all the other postings in the documents section here in the communities:
http://communities.vmware.com/community/vmtn/server/vcenter/orchestrator?view=documents
Cheers,
Joerg