Enterprise architects do need to expose their applications to the Web. However, simply exposing an enterprise application to the Web is not necessarily ideal. Properly integrating legacy systems and mainframe applications with the Web requires considerations for factors such as how the application was written or how scalable the system is.
In this brief video, Forrester Analyst Phil Murphy discusses important considerations for IT organizations that are modernizing monolithic mainframe applications.
Security is another important concern for the SOA architect. There is a greater risk of a malicious user accessing the application via the Internet, so the security aspect of access is another important consideration. There are many viable options for moving a mainframe application to the Web securely, but potential methods have to be well thought out.