Recently, I moved from the SOA Suite team to the Mobile Suite team. Oracle Mobile Suite is comprised of 2 main products, the ADF Mobile product which allows you to develop application in ADF and then deploy them as native apps on both iOS and Android platforms. The second product in Mobile Suite is Oracle Service Bus. As a result, many of the customers that I visit have asked me, "Why have Oracle Service Bus in the Mobile Suite?"
For a complete answer, I wrote a blog entry on http://blogs.oracle.com/mobile/entry/why_use_a_service_bus. Ceck it out and let me know what you think.