The following was recently posted on the official MapleStory site:

Maple Story's new user registrations for the beta test are now closed. We will no longer be taking sign-ups until further notice (Current users will continue to have access to the beta test). During this period, we will work on improving our website, preparing more worlds, and adding new features and content such as the highly anticipated land of Ossyria, the mini-games, and the cash shop. maplestory mesos. Thank you for making the Maple Story Beta Test a successful first step towards commercial service. We will continue to update you on our progress through the notice section of the website.