Here is my first attempt at defining a Web Services Fabric:
Concerns are the non-functional requirements (ilities if you will) - Scalability, Availability, etc.
Remedies are architectural components that attempt to resolve the concerns (clusters, etc.)
Every architecture has multiple components (database, presentation server, etc.)
Every architectural component has concerns (scalability, availability, security).
And every concern has at least one remedy (scalability is remedied by load balancing).
Every remedy has its own concerns (the load balancer must be secure).
And the concern to a remedy has at least one remedy (the load balancer will use secured authentication)
When the remedies to concerns leverage other remedies within the architectural circle, a consistent architectural fabric is created.
Service oriented architectures have the potential for creating such a fabric.
A service fabric is an integrated set of services that utilize each other to satisfy their architectural requirements.