Jonathan G. Blattmachr (Milbank, New York), Mitchell M. Gans (Hofstra) & Alvina H. Lo (Credit Suisse) have posted A Beneficiary as Trust Owner: Decoding Section 678, 35 ACTEC J. 35 (Fall 2009), on SSRN.  Here is the abstract:

This article explores the circumstances under which a person who does not contribute property to a trust can be considered its "owner" for income tax purposes. The article focuses particularly on whether the a beneficiary's power to distribute trust property to himself or herself, subject to an ascertainable standard, should be treated as the income tax owner of some portion of the trust property. The article then examines whether a holder of an unrestricted power of withdrawal that has lapsed may continue to be treated for income tax purposes as the owner of some portion of the trust property.