Unless you know of something new, this is a misrepresentation of an issue known as transaction malleability. Yes, exchange and wallet software developers need to be aware of it, but it does not allow the same coin to be transferred more than once.
If you know something new, we'd like the details.
From the article...
In MtGox’s case, it appears that what happened is that the site was expecting transactions to show up in the public ledger under the specific transaction ID it had recorded. When those transactions didn’t show up – because the thief had edited the ID – the thief could then complain that the transaction had failed, and the system would automatically retry, initiating a second transaction and sending out more bitcoins.Transaction malleability is a flaw in bitcoin itself, and it’s not MtGox’s fault that transactions can be renamed in this way. But it’s also a flaw which has been known about since 2011, and one which can be rendered harmless with software which accurately reports balances and transactions.