Nothing scarier than hearing about Unity 1.1 being released after Enterprise Library 4.0, but rest assured Unity 1.1 is included with Enterprise Library 4.0.

Unity 1.1 fixes a few bugs and has other enhancements:

Removal of all obsolete ObjectBuilder code.
Fix for a bug when using lifetime managers with open generic types.
Fix for a bug where the RegisterType method was overriding the RegisterInstance method.
Performance improvement when resolving singletons.
Exposure of some additional internal classes as public to make it easier write extensions that need to resolve dependencies in a customized way.
Addition of try...catch blocks to improve the error messages returned when value resolution fails.

You can download Unity 1.1 here.

More importantly, however, I had a chance to play with Enterprise Library 4.0 and Unity this evening and created a tutorial that shows you how to use Unity with the Data Access Application Block:

• Enterprise Library 4.0 Data Access Application Block ( DAAB ) and Unity IoC Tutorial - DataAccessBlockExtension

The other application blocks work similarly so hopefully the tutorial gives you an idea on how it all works.