For anyone that cares, we use multi-sig in our wallet solution at Atlas ATS. Any alt-coin that keeps up with Bitcoin development should support this.
I can atleast confirm 100% for LTC, DOGE

Here is withdrawal:
http://ltc.blockr.io/tx/info/2e14f864498c02ec0f6767d30b9229d94c6d446f0d407a0182d6bbb27183d2f0

Here is a deposit:
http://ltc.blockr.io/tx/info/f6edd17ffedd9fd0d335711c2c69fecb63b1134dbaf52771e63f03f2de119d3d

Unfortunately we have had couple of people who were unable to move LTC to multisig address because the exchange or wallet they use do not support them since they are still running legacy code. Certain block explorers would give you an error if you were to search by the multi-sig address but if you search by transaction hash you should see these transactions.

As someone pointed out it could be useful for people who want to hold huge amounts of BTC securely. But its about time we got a serious Bitcoin Bank who actually insures deposits.

+1 Max Keiser

Wow to openly allow people to sell their accounts while the rest of the forums rely on that to form trust does sound a bit ridiculous. I think a scammer tag is too extreme but some other kind of tagging should help prevent people from using these accounts for scam.

2 @ 7

$76