could XMR.TO be upgraded to act as a bitcoin mixer? receiving BTC converting through XMR back to BTC? Or how could that work? it would be a pretty nice service that is directly marketable to the bitcoin crowd and let them find out about ring signatures before some BTC sidechain tries to steals its glory
Not really for the moment...
The only way to avoid taint between the incoming and the outgoing bitcoins would be to have two completely, perfectly, absolutely separated wallets: one for the incoming bitcoins and one for the outgoing ones. The tricky part would be to transfer from the incoming wallet to the outgoing wallet without taint between them, and to do that converting to XMR isn't of any significant help unless you trade with two completely separated entities that cannot talk to each other to do (i) first BTC > XMR, then (ii) XMR > BTC. Currently it is not possible as we would need to rely on a very small numbers of entities (poloniex + few individuals), so at least them would know the taint trivially. If at least few entities can get the taint trivially, you have accomplished nothing and aren't doing much better than current bitcoin mixers.
Open to any suggestion of course, because I agree this would be very powerful.
i thought about:
Person 1 wants to send BTC anonymously
Person 2 has too much XMR
Person 1 sends BTC to Person 2.
Person 2 send XMR to Polo
Polo exchanges XMR to BTC
Polo Withdraws BTC to Person 1
Polo now knows that this person owns BTC. But not where the wealth originated from (e.g. paycheck, robbery)
Person 2 knows everything and can be bribed (e.g. if its the stolen BitStamp coins he can tell the Withdraw Address Person 1 used). He is also the person who gets contacted by authorities if he tries to send it to coinbase or anything like that.