MSDynamicsWorld has the scoop from the technical airlift. GP Rewrite: Microsoft prepares a brand new service-based Dynamics GP architecture for next release. Rewrite may be too strong a word, but it certainly sounds like a significant extension to GP’s architecture and it sounds like the GP team is invigorated. GP has always been an extensible platform and it sounds like the GP is again embracing that as a primary strength.
GP Rewrite: Microsoft prepares a brand new service-based Dynamics GP architecture for next release | MSDynamicsWorld.com
Archived post from 2013. Dynamics GP and the links it points to have changed since; check current documentation before relying on version-specific steps.