I had been a tube snob for as long as I have been playing guitar until I got a Revv G4. I'm blown away by how well it responds to picking dynamics, volume knob, etc. I use a Friedman Smallbox pedal for my hotrodded vintage tones, and it has a similar feel, but I'm sending that into the frontend of my amp, whereas the G4 goes into the effects loop return, so I can't say that it qualifies 100%. So as far as preamps go, solid-state is a completely suitable replacement.
I don't have nearly as much experience with solid-state power amps, and it's probably because my short time with an EHX 44 Magnum soured me. But I'm pretty sure newer items could compete with the tube-based power amps I've used. The Blackstar Amped pedals look awesome, and I'm sure I could get through a small gig with an Orange Terror Stamp.
To answer the original question, I think we're there with convincing solid-state analog technology.