The surviving spouse has the option of rolling over the decedent's IRA into one for the survivor, thus continuing the potential tax deferral (for a Roth IRA, the spouse must be the sole designated beneficiary).
Who_can_be_beneficiary.html
The IRA owner may name more than one beneficiary and specify a dollar amount or percentage of the IRA proceeds to be paid to each beneficiary.
Multiple_Beneficiaries.html