First, Danny Simmons post titled "Why use the Entity Framework" clarifies Entity Framework vs. traditional ADO.Net, Entity Framework vs. LINQ to SQL, Entity Framework vs. nHibernate etc.
Frans Bouma (LLBLGenPro etc) has a followup piece, titled Why use the Entity Framework? Yeah, why exactly?
Finally, included as a reference, Frans Bouma's essay titled The Database Model is the Domain Model is useful for anyone who's not read an awful lot about OR/M tools and needs a quick primer.
I'm mostly posting these for reference purposes, and partly as Doug might be interested in reading them (/wave) when he returns to places with Internet connections.