Estate of Timken, et al. v. United States, 601 F. 3d 431 (6th Cir. 2010), cert. den., 131 S. Ct. 905 (U.S. 2011)

(trust transfers subject to GSTT; grandfathering exemption for trusts that are irrevocable at time GSTT enacted is ambiguous as applied to exercise of a general power of appointment, and regulation which interprets exemption is reasonable and denies exemption for transfer at issue).