The guys from the Enterprise Library development team are taking feature suggestions for the upcoming Enterprise Library 5.
I have suggested the following:
A configuration editor for Unity, like ther is for all the other application blocks
A LINQ provider block
Inclusion of XSD schema files for all application blocks, so that we can have intellisense on Visual Studio
ADDED: Externalization of the code generation module, like LinFu (I had forgot this one)
You can submit your own here: http://blogs.msdn.com/agile/archive/2009/01/26/enterprise-library-5-what-s-on-your-wish-list.aspx.