Will any of the proposed Scripts (OP_XXX) allow subscription/recurring type payments? Is it possible to implement a subscription/recurring payment type using Bitcoin scripts? 

For example, you could send a payment for a service where there is a monthly subscription say, and each month if there was enough bitcoin in the paying address the required amount would be sent to the service provider. The time could be based on block number, which should correlate well with time, i.e. a monthly payment could be a payment every 4320 blocks.
In order to send someone Bitcoins, you need to sign a transaction with your private key.
Each transaction on your set of coins refers to the previous transaction. It is possible to create a daisy chain of transactions like this, but if you'd perform any operation in between the start and the finish of such sets of payments, the remaining transactions would be invalidated.


This makes it impossible under current model of transactions to perform such an operation. You could define a new OP that would allow one to redeem coins only after a certain amount of time, but then you'd be paying the full amount up front anyway.

You could, however, create a client that would be scheduling payments. But there is a problem - it is generally advised to keep your private keys encrypted, so nobody could steal your coins. A client can't sign a transaction with an encrypted key, so you'd have to be prompted for passwords every time. On the other hand, one could imagine a single address in a wallet to be kept unencrypted for such transactions. In the end though, it is not a matter of creating a new OP in the protocol, but new functionality in a client.