WS-* and REST are often portrayed as competing technologies. While the use cases they deal with do overlap in some cases, there are many instances where each will have its logical place in a given system architecture. Both WS-* and REST are focused on interoperability, so if any two technologies should be able to work together, it is these two.
REST's approach gives developers an efficient way to build and deploy web services using existing technologies that are typically already deployed and scaled out in the enterprise. REST does not provide frameworks to handle the declarative, configuration driven qualities like security, QoS, etc. that WS-* does, but that is not the point of REST. REST style services benefit from integration with security services such as authentication services that can provide increased assurance and security through strong authentication mechanisms like two factor, OTP, etc., as long as these services plug into the existing infrastructure that REST deals with.
Many of the core WS-* use cases are designed for transactional middleware systems like an enterprise service bus. REST was not designed for this purpose, though there are many cases where architects will want their REST services to integrate with their ESB. The goal of this integration is to enable the development and deployment efficiency gains that REST to plug into systems like an ESB and other WS-* systems by bridging the protocols with a STS that brokers communications and allows for a robust, integrated security model.
So what does all this mean to security architects? WS-* has a very useful set of security standards and tools. REST does not. WS-* has ways to deal with securing identity, messages, tokens, etc. while securing REST is more analogous to securing a web app - things are likely to be much more unstructured and customized. Each requires an unique security model, the integration point between the two security realms benefits from interoperability in the security service like a STS that exchanges tokens between the two realms.