To many seasoned architects, developers and SOA proponents, the REST versus SOAP-based Web services argument is old news. Nevertheless, it helps to understand where each set of protocols is the healthiest fit in enterprise applications. Alan Earls of SearchSOA provides a good refresh on the evolving role of REST, which can be found in many an SOA effort.
The general consensus about REST is that it while it is more lightweight and faster to implement, and very effective for generating open APIs that enable broad interactions with business partners or customers. However, it may not be appropriate for heavy-duty enterprise work. As best-selling IT author Thomas Erl puts it:
“REST constraints do not conflict with service-orientation principles. In fact, several REST constraints directly support and enable service-oriented design requirements. However, applying some service-orientation principles to their full extent can raise design issues that may limit the extent to which some REST constraints can be applied. This is especially a consideration when designing sophisticated application integration solutions comprised of service compositions."
There is a fault line between REST and SOAP Web services -- consumer versus enterprise applications. IN Alan's article, Gartner's Daniel Sholler says this shapes the nature of service orientation between the business and consumer worlds, "with the former still prepping for SOA and the latter running full speed for REST."