I've been lurking on this thread for a while, & finally caved and made an account so I could reply...
I did hear from UCI right away - submitted my application shortly before the Jan. 15 deadline, heard back from the head of doctoral studies by Jan. 23 asking me to come in for an interview. I couldn't go down to Irvine the available dates, so I interviewed with them via Skype instead, on Jan. 29. I haven't heard anything more since that interview, though. I went to UCI for undergrad and took classes with a few of the professors on the committee (they wrote letters of rec for me for my current MA program, actually, and had suggested last year that I apply to UCI's PhD program), so that may have had an effect on the speedy response to my application. Like I said, though, haven't heard anything of any kind since the interview.
Hope that's helpful and not just further stress-inducing...!