As others have pointed out, I think getting refunded in USD equivalent is fair IMO, because if BTC was worth $1 today, I don't think a single person would complain about getting a USD refund, and demand they are paid back in worthless BTC that's worth a fraction of the USD it was at the time of purchase. There are numerous sources that accept BTC, if it becomes a game of 'refund me my BTC if it goes up, and USD if it goes down', I can see why business are hesitant on accepting Bitcoin at their business. You've virtually made it a lose/lose for businesses.
Most businesses would hold BTC until they shipped the product. It is only too risky for companies like BFL that don't ship for months on end.
Also, there are numerous examples of comparing BTC to Yen, Euro, USD, etc.. I think the prime difference in these cases is all of those are federally recognized as currency by governments and world bodies. BTC is not. Trust me, I want BTC to succeed as much as anyone here does, and I strongly believe digital currency is the future. However, because a group of people on the internet say Bitcoin is a mainstream currency, the courts (as far as I know) say differently. Maybe years down the road this will change, but I can't see a single judge seeing it this way as of now.
Bitcoin is not a currency in a general sense, it is a journal of past transactions in the public record. The block chain will not contain a record of BFL receiving your Bitcoins, as Bitpay received the Bitcoins. Good luck trying that one out on a judge, not that it would ever get that far, as to my knowledge BFL have not refused a refund of a pre-order to date, if they have nobody has screamed about it here.
Actually, FINCen just issued guidance on this and they do call it a currency, but Bitcoin has not yet been tested in courts. Other virtual currencies have been tested (airline miles, facebook credits, etc) and it is not too much of a stretch to establish them as precedent.
http://fincen.gov/statutes_regs/guidance/html/FIN-2013-G001.html