I'm also waiting! In case it helps, here's some info I only recently noticed on UCI's website:
All offers of admission will be made by March 25. These candidates must accept or decline their offer and financial support package no later than April 15.Candidates who have been placed on a wait list will also be notified by April 1, and offered admission and support as places become available.Applicants who have not been notified of admission or placement on the wait list by April 2, should assume they will not be offered admission. Because of the high number of applications and limited staff, it is not possible to send out denial notifications until late spring. Applicants who wish to confirm their application status sooner, may contact the Programs in Writing after April 16.