(1) If such failure occurs simultaneously with the death of the trustor, the trust principal not effectively disposed of shall be treated as though it were an additional part of the trustor's estate, and shall be disposed of in accordance with the provisions of the trustor's will, or if the trustor has no valid will, then the provisions of § 501 et seq. of this title shall govern the disposition of such principal; provided, however, that if any disposition to the trust would be treated as a qualified disposition, within the meaning of § 3570(7) of this title, if paragraph (2) of this section, rather than this paragraph (1), were applicable to the trust, then the principal of the trust shall be disposed of in accordance with paragraph (2) of this section.

(2) If such failure occurs at any time other than simultaneously with the death of the trustor, the trust income and principal not effectively disposed of shall be distributed as though the trustor had died on the date on which such failure occurred, a resident of the state of Delaware, owning the property so distributable, as though the provisions of § 501 et seq. of this title applied, but provided that if the provisions of § 502(2) or (3) of this title would apply for purposes of determining the share of a surviving spouse, the share of such surviving spouse shall be half of the personal property of the trust plus a life estate in the real estate of the trust.