I have been writing a series of posts recently about implementing a custom WF activity that will provide dependency resolution support for WF4 workflows.
The InstanceResolver activity caters for lazy loading dependencies, multiple resolutions on the one activity, workflow persistence (including support for non-serializable dependencies) and lifetime management of the resolved dependencies. The activity uses Unity as the backend IoC container however this could be modified to support a different container with minimal changes.
The following is a list of all the posts in this series.
This workflow activity and several others can be found in my Neovolve.Toolkit project which can be found here on CodePlex.
Tags: WF, Dependency Injection, Unity