Where does homomorphic filtering stand in regards to DSP applications? I am studying my Oppenheim and Shaffer book, (New Edition), and the last chapter deals with something called homomorphic filtering. I have read the wiki and some other websites about it, but they do not really delve into details on applications. Moreover, I have almost never heard of it be brought up in discussions or recent papers, etc. 

So what are some applications of this processing, and why/how is it so quiet out there in regards to it? Is it because it has been overtaken by more advanced techniques, or is it just too clunky or some other reason? Have you used it before, if so, for what purpose?
The cepstrum, or cepstral analysis, which is one form of homomorphic processing, has been used in music and speech analysis to estimate the deconvolution of source (exciter) pitch and vocal tract (and/or other) resonances; sometimes just used as a music/speech pitch detection/estimation method, but also useful for formant tracking as well.