It may be worth noting that Bitcoins are also uniquely identified and can be traced back through all transactions.
Unless there's some way to associate addresses as coming from a single wallet, which I do not think is the case.
There's no way of identifying the person reliably, if s/he doesn't disclose a name.
Using proxies seems like the digital equivalent of using middlemen for cash transactions. If I use enough middlemen it will be really, really hard to identify me reliably. Any differences I've missed?