Hi, I am still waiting on Columbia advanced standing as well. Got into two other schools, but Columbia is my first choice.
Going crazy with anticipation, and spoke with admissions who let me know I am still under review, and not in a waitlist situation yet. They said its not unheard of for advanced standing applicants to hear back late April/May. Hopefully I hear back sooner rather than later.
Applied: Columbia, Boston University, University of Toronto
Accepted: Boston University, University of Toronto