Several new OBA case studies have been published recently. Good insights into how others a leveraging and reaping the benefits of OBAs. 

Approva estimates it cut development time by up to 33% using the Microsoft Office and associated ecosytem

http://www.microsoft.com/casestudies/casestudy.aspx?casestudyid=4000000530

Convergence Communications boosts marketshare with its OBA solution

http://www.microsoft.com/casestudies/casestudy.aspx?casestudyid=4000000120

WorkflowOne gets rapid returns with OBA

http://www.microsoft.com/casestudies/casestudy.aspx?casestudyid=201201

- Khawar