Mark, not to hijack the thread, but could we also allow discussion of innovations in tools and processes for development and construction of pedals?
Hijack away, my friend. AFAIC, if its something that moves the field ahead, then it counts fair and square. Clearly Electrosonic thinks that way too, by his mention of small-run PCB fabrication.
I also agree with others that the PT2399 has made an enormous number of interesting things possible for peanuts. I find it amazing that a chip one can get for under a buck will do a great deal of what my old MXR Digital Delay does for a teeny fraction of the cost and size...and with more fidelity and delay time to boot.
I don't know if it qualifies as an "innovation", but the presence of tiny (9mm) PC-mount pots, and those delicious narrow profile Davies knobs that Steve Daniels had resurrected have made it possible for analog devotees to squish a crazy number of controls in a small footprint.
And of course, many people would probably agree that the various Molten Voltage chips that permit easily implemented tap-tempo, etc., have been very helpful.