CDCK solution may be implemented in addition to 3D Secure or any fraud scoring system - this could be great tool for active and knowledgeable cardholders and good way for bank to show that it cares about cardholders' money.

I would actually see CDCK solution role as a supplementary system rather than alternative to 3D - because of a tiny detail:
3DSecure provides explicit cardholder approval of transaction - like "I, cardholder, approved and made the transaction", whereas
CDCK provides cardholder control on card blocking - like "I, cardholder, opened the card for transactions for given time period". This detail makes difference from legal point.

Both are great but they have different goals so they are not really comparable.

In some countries local banks offer a service whereas cardholder receives a SMS for each posting to (card) account - this allows early detection of fraudulentunauthorised charges. I understand that to be somewhat similar to CDCK payment acknowledgment process. And i think that some are offering (or contemplating to offer) the service to switch ON/OFF cardholder cards via internet bank.