I'm not trying to promote bitgo, but the idea that you can do multi-signature properly with bitcoind alone is completely untrue.  You at least need some additional software for routing partially signed transactions to appropriate stakeholders, and better yet you need a service that applies fraud detection rules similar to those used at visa, mastercard, paypal, etc.

Things you can't do with bitcoind alone:
a) Basic fraud checks (based on geography, user patterns, etc)
b) Spending limits and velocity limits. 
c) Verify that funds are not being sent to known scam addresses (someday these lists will be as large as email anti-spam blacklists)
d) Enforce specific whitelisted addresses to send to
e) Lockdown transactions to be only originated from certain IP addresses or machines

The list goes on and on.  Granted, if you've only got a couple of bitcoin, you don't need all of these protections.  But, if you've got serious holdings, you absolutely do.  Blanket statements that bitcoind's multi-sig is good enough for all levels seems pretty false to me.

Mike