I applied but haven't heard anything myself yet. Their website indicates it will happen in January. Here is what I copied and pasted off their website:
http://www.columbia.edu/cu/psychology/graduate/prospective/application.html
Admission - The Interview Invitation
In January, selected students will be contacted by faculty either by phone or email and invited to attend ‘Prospective Days’ at Columbia. Prospective Days are held over a long weekend in late February so these applicants can gain a first hand knowledge of the Psychology faculty, the current students and the program in general. It also provides the faculty with the opportunity to interact with prospective students to determine the degree of matching interests. The final selection of students occurs after this weekend.
While students who will be admitted will be contacted soon after by the department, the formal offer will come from the Graduate School of Arts and Sciences in email. Official notification from the Graduate School of Arts and Sciences about admission decisions will be mailed mid-March.
