So says the official blog.

To quote:

On top of that, we have good news for all our Sanriotown users. If you’ve taken time to check the mail info box that appears when you log-in to Sanriotown, you’ve probably noticed that you have a certain number of “Kitty Points”.

In Open Beta, these Kitty Points will be converted into HKO Loyalty Points. That means, the higher your Kitty Points, the more Loyalty Points you will receive. This will be an active conversion system, so continued use of Sanriotown will earn you more points for the Item Mall!

At the moment, signing up, logging in, sending email through your account will earn you Kitty Points, but we have plans to extend this system to the use of other services in Sanriotown.

This means I get to use my Kittypoints for credits inside the game once launched.