If I understand correctly this patch will allow web application servers running bticoind to confirm payments without an active receiving wallet.
I would like to reiterate that this is an important feature. Since the mybitcoin debacle there is now a deadlock for merchant services between the risk of a server side wallet, and the risk of 3rd party merchant services. I am shocked to find out that getreceivedbyaddress does not give a correct value for any address except those in your wallet. This means that a receiving wallet must be left on the server and it will receive ALL bitcoin income for the service. Even with code to regularly sweep the account, this is clearly an unacceptable security risk. On the other hand all 3rd party solutions are even riskier.
Conscientious merchants simply can't move forward with bitcoin without this patch.
j
This is part of the reason I stopped using this patch myself. At the moment I am trying to stabilize blkmond, which provides a realtime view of the whole Bitcoin network, including all transaction activity, but likes to stop running unexpectedly. It can notify of payments received at an address without access to the wallet containing the corresponding key, but not if it's crashed.