I'd definitely advise against a refund, because you can sell your place in line to someone else. If BFL's very slow or shipping a few prototypes which'll never be remade, put that risk on someone else and collect a small sum extra over just getting a refund.

Generally, because BFL has some dislike of preorder resales, you have the units shipped to the same address (yours), then ship to the buyer once the product's in your hands. Oh, and you should use free escrow (mine, merely for example! ).