Well... not really. I haven't had time to play with it.
But today I came to this thread in the Alt Dot.Net Discussion List. Normally I don't look very much at it, amongst other things it's because a lot of stuff happens there and I can't keep up with everything.
I even did not finish reading it, because it turned into criticism to the whole Pattern & Practices (P&P) and Enterprise Library (EntLib), Microsoft's position in regards to OSS and because... well, I have to do some work in the timeouts when I am not deploying stuff to my Moss VM.
As I said, I haven't played with it, but I have had some play and even "serious" work with others containers so I will myself have some opinion some day.
The point is, I do not find fair all the bashing to EntLib. It may be over-engineered, it may be difficult to get your hands upon all the configuration needed to get it running, it may be also difficult to follow the source code if you need to extend it. But I think it deserves some credit. And so do the guys behind it.
It has helped me to save a lot of code (I'm thinking on early Data Access Block and the nice Caching Block in the 2.0 version) and I am sure it has helped others to, at least, think about what "Best Practices" are (although not all that it brings with it are necessarily even a "Good Practice") and how to apply them to their code.
Am I going to use some of its features again? Hell, yes.
It's the answer to all of our prayers and the one and only solution for all of our problems? Hell, no.
But I do not know any development tool (Commercial, Free, OSS, Shareware...) that is. Do you?