It has been awhile since I last published a pattern draft - but I guess it is better late than never.
The saga pattern deals with manginc complex interactions between services without the use of atomic transactions, which as I mentioned in the past are not a good idea (see "Transactions between services? No, No, No!" and "Some more thoughts on Cross-service transactions" )

You can download the draft for the Saga pattern from here.
I'll also add a link to it from the SOA Patterns book section (where you can also download the other pattern drafts I published)

By the way, I am not happy with the current  sketch (the pattern illustration) in this pattern, so it will probably change in later drafts. I would be happy to hear any suggestions you have for improving it.