I've always thought this would be the perfect effects solution. An analog signal path that can be controlled digitally. So rather than an A/D/A system and digital effects, you simply use the digital to operate the controls of an analog circuit. So the tonal quality of an analog pedal, with the versatility and quick-change of a digital setup.
So far, I've only seen a single example of this by Vintage Revolution. It's designed for guitar, rackmounted, has 14 effects, and costs a LOT of money.
http://www.vintage-revolution.com/products/pedalpro/
Anyone heard of other effect makers using a similar methodology for an analog multi-effect pedal?