Uncomfortable though it might be, holders of BTC on MtGox need to realise that their interests in a bankruptcy are fundamentally opposed to those of USD holders. The right thing to do for BTC holders is to file a second class action seeking to enjoin MtGox from allowing any withdrawals until it can prove it holds sufficient funds to cover both all USD and all BTC deposits.

MtGox has very short terms and conditions; go read them. They make exactly the same warranty on currency holdings and on Bitcoin holdings; thus in an insolvency the Bitcoin holders should seek equal preference. The USD holders would obviously seek to see their USD holdings cashed out before the BTC holders are even looked at, but that's terrible for the BTC holders. It's also very likely to be unfair preference.

What does that mean practically? That all the USD holders could end up with court orders to return their withdrawals.

Oh, and no cheeky conversion of BTC to USD at MtGox's rate, either. Holders of BTC are entitled to fair value. A marketplace in insolvency is by definition not a fair means of valuing assets.