I have seen several other ideas with respect to admins or bosses needing the ability to delegate on someone else's behalf. Totally awesome ideas and would love to see it. We have had it happen lots of times where people leave on vacation and forget to delegate. Their boss or a sysadmin should have the ability to delegate on their behalf.
One extra spin here: I would also like to see the ability to delegate approvals by module. Eg. I want Joe to handle my RFC approvals and Connie to handle to my Request approvals while I'm off. This flexibility is critical when people play multiple roles in the organization.