There are a number of reasons to choose Atom Protocol as the substrate for web-scale reliable messaging. First, a ton of software will be written to target APP in the next few years, and there is plenty of scope for extending the protocol; this suggests openly available and flexible software stacks. Second, since all document collections in Atom Protocol are served as Atom Feeds, it has inherent support for systems management and end to end reconciliation. Third, Atom entries have identity and are natural envelopes, unlike SOAP, where identity and true enveloping requires further specification (essentially raw Atom presents a better basis for interoperation than raw SOAP). Fourth, Atom Protocol can support binary content transmission not just XML, and thus can transmit arbitrary payloads. Finally, because Atom Protocol respects media types and deployed HTTP infrastructure, independent proxy inspection and security check-pointing can be installed cleanly, also eliminating the need to rewrite 2 stack layers and buy XML appliances to support and secure SOAP backed web services. It seems to be a question of when, rather than if, this will get built out.