This is great news for Enterprise Library Developers! Enterprise Library is now on the official Nuget Feed. You can add package references from within Visual Studio to the various Enterprise Library Application Blocks to pull them down and their dependencies.
All of the Enterprise Library 5 Application Blocks are on there and I noticed a few references to Enterprise Library 3 and 4 with respect to the DAAB and Logging Application Blocks.
Of course, you'll still need to install Enterprise Library on your development PC so you can use the Enterprise Library Configuration Editor. Having the various EntLib Application Blocks on Nuget just makes it easier to add and remove them from your Visual Studio Projects.