The leads tab now allows you to organize your leads by statuses set by your company. You can manage these statuses under the "Manage" tab at the top of your screen. You will need to go to Manage > Leads > Lead Status Management.
Once in Lead Status Management, you may add new lead statuses by clicking the "New Lead Status" button in the top right corner of your screen. You may also edit/ update and delete current lead statuses.