Today, Twitter staff members announced to their developers that they will be removing the 140 character limit in direct messages sometime in July.
While the limit will remain for regular tweets, it will no longer be imposed on direct messages. This announcement was made along with the new API additions for developers to prep their apps for this change.
The great news about this is companies like T-Mobile that provide customer support over Twitter DMs will no longer have to attach the rather annoying “2/3” notation at the end of their messages to let you know that the next message will be a continuation of the previous.
The removal of the character limit has no specific implementation date, but one will be posted in the forum post once one has been determined.