So anyone who's worked on projects with me knows I'm an advocate of using the Enterprise Library for addressing typical cross-cutting application concerns. Enterprise Library 4.0 was released yesterday which now works with Visual Studio 2008 and the netfx3.5 and includes the Unity IoC application block.
The Application Block Software Factory and Strong-name Guidance Package have been removed from the entlib but are said to be available as separate downloads/projects, presumably on CodePlex (haven't yet located them). I look forward to revisiting them, though, and hope the issues have been resolved since their initial release in entlib3.
I for one was no fan of either as they were released broken or half-baked with entlib3. Simple ABSF app blocks needed significant manual manipulation once the guidance steps were completed. And the SNGP dropped distinct .snk files in each project folder rather than adding links from a shared folder, it didn't address deployment scenarios, and had no options for those with existing project and solution standards.
The Unity IoC Container (or Application Block) has been available stand-alone for some time now but it's a great addition to the entlib4 line up for managing dependencies and mapping/resolving interfaces to concrete classes at run-time or for generating instances of entlib objects. If you've not yet taken a look at Unity you should.