The following is part of what was just posted in the main Monero thread and I am posting it here as there has been requests for more info.
Shen's comment regarding ring multi-signature:
All updates, whitepapers etc. regarding Ring Confidential Transactions (CT) can be found here -> https://www.reddit.com/r/Monero/comments/3pw30d/ringct_for_monero_updated_versions/
Thank you for posting this here. Combining multisig with CryptoNote (particularly with CT) opens up a lot of possibilities for much better security when doing business with unknown parties without the need for 3rd party escrow. In fact it is hard to imagine how bitcoin could compete in that context for transactions where privacy is important. Multisig will help tremendously.
Right now bitcoin still has the advantage in liquidity, network hash rate, adoption, acceptance (xmr.to neutralizes the adoption advantage for small transaction sizes. Hopefully xmr.to will allow larger transactions as liquidity improves) and multisig.