This is a nice introduction to the technology, but I think it's a bit heavy on the technology and not informative enough about the historical context and the problem space. Take this section:
"Today, we face complex issues like distributed software, application integration, varying platforms, varying protocols, various devices, the Internet, etc. Today's software has to be equipped to answer the call for all of the above."
It's my understanding from reading the article that these two lines provide the justification for SOA. In order to do that, more depth is required. Why do we need distributed software? How does SOA provide a better application integration solution than other EAI approaches?
Then there is the historical aspect of the discussion. There is some high level software engineering history but there is no discussion about EDI or other interchange standards.
A whole article could be dedicated just to providing a historical context and issues based justification for SOA. It's that article that would be valuable.
In other words, write an article that shows me that web services with XML is a good idea that fits the problem and is superior to all existing standards. That web services over XML is not another EJB-style Sun hype fest.