I\'ve been playing with ADO.NET Entity Framework lately, and I find that it suits my needs for a project I\'m developing. I also find cool its non-invasive nature.
A
One of the big critiques against the Entity Framework has been that it is inherently hard to test, for example in the ALT.Net Vote of No Confidence that gef quoted.
Here is a blog post discussing how to get around this, and be able to test your code without hitting the database, when using Entity Framework.
If testability is a big concern, you might want to look at another ORM framework, such as NHibernate, at least until Entity Framework 2.0 is released.