I was thinking of a way to locate addresses belonging to Mt.Gox, which would require users cooperation but
could possibly help a lot. Please forgive me if someone already thought about this and is actively working on it; if this is the case, please point me to the relevant discussion(s) and/or people.
The idea is this: all the Bitcoins Mt.Gox had have been deposited there by users at some point in time. These deposits have been made from their wallets to addresses provided by Mt.Gox, and the history of these deposits can be recovered from users' wallets. Thus we can, at least theoretically, build a database of all (or most of) the addresses through which Bitcoins have
entered Mt.Gox.
As soon as the Bitcoins entered Mt.Gox, it's reasonable to assume they have been moved from their initial deposit address to hot wallets and/or cold wallets; it's also reasonable to assume this has been done rather quickly, probably by some daily/weekly automated process. Thus, by looking at transactions from those initial deposit addresses, we should be able to find Mt.Gox's wallets easily.
The problem here is: how can we find the deposit addresses of Mt.Gox users?
This data can be gathered by someone who is already actively working on the Mt.Gox crash and has already gathered some data on their customers, like the guys at
http://mtgoxrecovery.com. I suggest they provide a form for their users to submit the amount of BTCs they deposited into Mt.Gox and the deposit addresses they used, or, better yet, the transaction IDs of their deposits. Then some real investigation could begin.
Also, they should at the same time ask for the transactions by which users
withdrew Bitcoins from Mt.Gox; this information can be used to stop tracking Bitcoins that left Mt.Gox and already returned to their rightful owners, and only focus on transactions which are (presumably) internal to Mt.Gox's system.
Of course, these information should be provided by users on a completely voluntary basis.
(N.B. I'd have suggested this to the owners of mtgoxrecovery.com myself, but I can't find a way to contact them...)
