(WF4) Workflow 4.0 Hosting Extensions

[Update:Dear Readers,To those of you who found this post interesting, but still a little too vague on how exactly you can use extensions for workflow-host communications, how this ties in with bookmarking, or what might be involved in implementing your own custom Send/Receive semantics in a workflow activity, you may enjoy the sequel post ‘Workflow 4.0…

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