NLRB to reconsider standards for deferral to arbitration?

The NLRB has invited briefs on the question of whether it should modify its standards for deferral to arbitration awards. The Board's General Counsel has encouraged the Board to revisit this issue as explained in GC Memo 11-05 (here).

Specifically, the Board has requested briefing on the following questions:

1. Should the Board adhere to, modify, or abandon its existing standard for post-arbitral
deferral under Spielberg Mfg. Co., 112 NLRB 1080 (1955), and Olin Corp., 268
NLRB 573 (1984)?

2. If the Board modifies the existing standard, should the Board adopt the standard
outlined by the General Counsel in GC Memorandum 11-05 (January 20, 2011) or
would some other modification of the existing standard be more appropriate: e.g., shifting the burden of proof, redefining “repugnant to the Act,” or reformulating the test for determining whether the arbitrator “adequately considered” the unfair labor practice issue?

3. If the Board modifies its existing post-arbitral deferral standard, would consequent
changes need to be made to the Board’s standards for determining whether to defer a
case to arbitration under Collyer Insulated Wire, 192 NLRB 837 (1971); United
Technologies Corp., 268 NLRB 557 (1984); and Dubo Mfg. Corp., 142 NLRB 431
(1963)?

4. If the Board modifies its existing post-arbitral deferral standard, would consequent
changes need to be made to the Board’s standards for determining whether to defer to
pre-arbitral grievance settlements under Alpha Beta, 273 NLRB 1546 (1985), review
denied sub nom. Mahon v. NLRB, 808 F.2d 1342 (9th Cir. 1987); and Postal Service,
300 NLRB 196 (1990)?

Update: The NLRB has issued its decision in Babcock & Wilcox Construction Inc. substantially modifying its approach to deferral to arbitration awards. The Board's decision can be found here.
The Board's General Counsel has issued a memo to the Regions on implementing the Board's decision. here