I continually experimented with automating sound-reactive video, but it was unpredictable and difficult to get a pleasing, "fluid" result which didn't cause seizures, so we always did it by hand using hardware such as EDIROL V-4 or the MX50. It was also a lot more fun to punch buttons and slam sliders to the beat of the music ;)
Do you mean current or previous pipeline? Unfortunately most projects are somewhat unique and require at least some variation, if not a complete overhaul in workflow, depending on what the customer wants. I never got a chance to use VVVV in a commercial capacity, although there is an upcoming project where we are seriously considering it. Generally we used custom in-house software (e.g. for 360 projections using 2x 4-channel MPEG-2 decoder cards) or VJ software such as ArKaos and Resolume. Like I said before, these days it's purely content production, so the pipeline is relatively similar to a game studio. We still encode everything into various QT formats and we rent hardware for shows because as you said, it's hard to keep up with ever-changing hardware demands.
If you are interested in our projects, check out http://www.motionlab.at (go the old site for now, the new site is WIP).
The V4s still sell quite well for some reason, some of the other analog gear is still in demand for circuit bending.
If the projectors are decent they can still hire pretty well too.
Keijiro Takahashi at Unity Japan has a great github repository full of relevant libraries.
Edit: low res demo from 2008: https://vimeo.com/2577056