This feature is only in the earlier rollout for some developers only and due to get a positive response then Microsoft has now released it for all developers WP.
To use this feature you just visit the Dev Center , select Dashboard for Windows Phone, then select one of the apps that you've published. After that look at the reviews and at the bottom of each review will there Respond button on the right. Just click the button to start replying to reviews.
In addition to adding these features Microsoft also added the option of payment through Paypal developer. But as usual, from 41 countries were added pembayarannya..Indonesia not included.
So developers, please check your Dev Center account each and just try this new feature. : D