As you require your application to be open for sharing and information within a network of components, in a Web 2.0 fashion, you'll want to integrate technologies such as web services, REST-based information publishing, and so on.

A good place to start your investigation on how to integrate the web services functionality to your applications is to look at Apache's CXF distributed OSGi sub-project, which implements the OSGi Remote Services specification (Chapter 13 of the OSGi 4.2 Compendium Specification), as well as the OSGi Remote Service Admin specification (Chapter 12 of the OSGi 4.2 Enterprise Specification).

Apache CXF Distributed OSGi service provides access to your services through SOAP over HTTP (by means of a WSDL description), as well as through JAX-RS, among potential others. Using a bundle activator to expose a web service using CXF boils down to registering the service along with a set of dictionary properties.

Alternately, you may also want to look at using Spring Web Services or embedding Axis2 in your service platform to provide the web services' functionality.