Can the buyer for a short sale property assist with expediting the process?

Unfortunately, due to laws regarding disclosure, the lender is not in a position to discuss the details of the transaction with you.

When a Realtor lists a short sale property the homeowner grants permission to the lender to allow the Realtor to discuss the financial information regarding the property sellers. 

The best you can hope for is to have your agent keep in persistent contact with the listing agent. When they know something you will know something. Everyone in the transaction is working for you (seller and both agents) because the seller wants to sell and the agents want to get paid. The only roadblock is the lender who is losing money.

Short sales are a test of patience.  Lenders do their own thing in their own sweet time.  Unfortunately as the buyer you cannot get involved in the process.  From a listing agent's point of view the best way to move things along is to remain in constant contact with the person in charge of the file.  Some lenders are more responsive than others and if the seller had more than one mortgage the process will take longer since there are two lending institutions to deal with. 

You can contact your representatives about the process but until the lenders get a plan that makes business sense and a short sale actually personally effects a representative I don't see much hope in that approach.

Banks are still financed by investors and run by individual boards of directors so every one has its own procedure for processing short sales. 

Hang in there, we really don't need any more legislation about how to run businesses by people who don't know anything about business.