@md600
He can, but only in the state of issuance (and
afaik only to the level of PPL), i.e. with a JAR-FCL CPL issued by germany you can fly N-Reg in germany but not across any border. If you want to ferry a N-Reg AS350 from France to Germany you'd either need a FAA license or two pilots, one with a french issued JAR/EASA license and another one with a german JAR/EASA license.
The difference between now and before 08th April 2012 (note: the implementation has been postponed - inofficially, remember this is not law ... still) is: Before you were allowed to fly N-Reg on a FAA CPL across europe acting as PIC in commercial transport even as a non U.S. resident (i.e. living/working in europe). Now you'd require a JAR/EASA CPL.
Similiar to the U.S.? Well, the only difference being 9-14(?) theoretical exams and practical exam incl. typerating (FAA => EASA) vs. reading two books, nailing PPL and CPL theoretical exams, oral (to me this seems the hardest part) and practical exam after 5(?) hours of instruction - imho definately worth the time to spend at a foreign airport if you never flew in the US before (EASA => FAA).
Please bear with me if i mixed up important details but i think you get the idea.
To me it is terrible to see what EASA-FCL has grown into and the 'implementation' is even more embarassing.