This article appeared in Web Services Journal, July 2, 2004. Author of the article - Amlan Debnath.
http://www.sys-con.com/story/?storyid=45517&DE=1
This article provides good overview of motives of BPEL and reason outs why BPEL is the core of web service. Author says that BPEL is designed with asynchronous services at its core, but this complicates the process of building a scalable, reliable BPEL engine. Author explains functionality of BPEL process using a simple order management process. Author figuratively explains evolution of application and server platform. Author provide overview of other key standards that are being developed, which are Extensible WSDL Binding Framework (JSR-208), Process Flow Coordination (BPEL), Reliable Web Messaging (WS-Reliability), Security (WS-Security), XML Data and Transformation (JAXB, XQuery), User Interactivity (WSRP), and Choreography and Contracts (WS-CDL). Even though author suggests that many standards are less mature, he believes these developments are going to dramatically change how we build applications and that the application server and BPEL are at the core of this new wave.
I also agree with author that even though many standards are still immature, web services is going to stay and success of web services depends upon success of BPEL. It is good to see industry recognizes this fact and actively working on to produce better tools.