MS Entity Framework VS NHibernate and its derived contribs (FluentNHibernate, Linq for NHibernate)

Question

I just read this article about the Entity Framework 4 (actually version 2).

Entity Framework seems to offer a huge improvement over its first release. Thus, I have never

Answer 1

Will EF4 tend to be less XML-verbose?

In general, I have not seen any indication that the XML will be drastically different. Microsoft is providing a Fluent like interface to EF in v4, but it's an add on / separate download.

Will EF4 be compatible with other underlying datastore than just SQL Server?

It is compatible now and it will remain compatible going forward. LinqToSql is SQL Server only, but EF has never been SQL Server only.

What are the greatest benefits of going with EF4 instead of FluentNHibernate or NHibernate itself?

Honestly, there aren't many. There are little things here and there that are different, but in general NHibernate is still years ahead of EntityFramework, even in EFv4.

As a consultant, it is probably worth your time to become an expert in both NHibernate and Entity Framework. You will probably continue to see them both in the real world. Microsoft tends to have a short attention span when it comes to data access so it's not clear where Entity Framework will be a couple of years from now. Because it's from Microsoft, you can be sure that plenty of developers will use EF.