Limited term assignments: a reader writes ...

One of this blog's readers has posed the following question and would welcome responses (posted below as comments, please!):

"In an assignment of copyright for a limited period (where ownership is assigned for a period of, say, two years and thereafter the ownership will revert back to the assignor), is it possible, or reasonable, to insert a clause into the assignment agreement that the assignment (which is essentially a sale of the copyright) is personal to the assignee and shall not be directly or indirectly transferred, disposed of, encumbered or shared with any party, other than on the express terms of the assignment agreement? Can the new owner of the copyright, albeit only for a limited two year period, be restricted in this manner?"

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