What is the impact of an inventor’s publication of his invention before filing which may be excused as “prior art” under the grace period? 

Under the literal wording of amended 35 USC § 103, this publication is also part of the state of the art for determining obviousness that is outside the literal wording of the grace period. 

Westlaw Monograph:  The attached paper,  “Shifting Sands: An Evolving State Of The Art Over Time(Death of a Reliable Patent ‘Grace Period’)”, is based upon the author’s monograph, First to File Patent  Drafting: A Practitioner’s Guide, particularly §§ 3:2 to 3:7, Grace Period of Apparent but Realistically Minor Value (Thomson Reuters forthcoming 2016).