>>http://ayende.com/Blog/archive/2010/01/05/nhibernate-vs.-entity-framework-4.0.aspx
>>
>>There isn't much of a comparison. Microsoft should just scrap EF and adopt NHibernate as their official ORM solution.
>
>Terrific. I just received an EF book from Amazon yesterday, planning to read it on the train. Maybe not the best investment of my time at this point?

Maybe not the best investment but not bad either, IMHO. It isn't just EF and nHibernate doing ORM but I wouldn't add a 3rd (which maybe better than both for the time being:) Learning never ends and I believe with the other projects going within MS learning EF is never a dead investment but a good one.
Cetin