If I could have a mythical beast, it would be VST(amp sims, FX suites, etc) loadable with MIDI control easily integrated and a tube pre(buffer) and power section in a head format. Obviously a smaller non powered pedal board friendly version would have to come out later after much whining.
Basically Build-a-Bear for VST guitar/bass software
I'd be all for such a thing - in fact, quite way back in the days I was considering either buying a Muse Receptor or building myself a very sturdy rackmount PC.
But for certain reasons, as far as my main live sound central goes, I rather stick with something proprietary, keeping me away from all kinds of experiments possibly bricking the unit.
Fwiw, it actually won't be *too* tough to build something like that yourself. Laptop based setups are rather common for keyboarders already, and while I wouldn't use a laptop for a guitar setup (where to put the thing?), one could get the cheapest Mac Mini, a Motu M2 (or an RME Babyface if you have some more money to spend), an iPad (could basically be any) and whatever MIDI controller to suit your needs. A Mac Mini can be shockmounted pretty much similar to a condenser mic without wasting too much space, and as there's really only one moving part inside anymore (the fan), things are rather safe. The iPad could then be used to remote control everything, from all I know.
All you'd then need is a live host, for most people MainStage should just do the job, for more advanced operations there's Gig Performer.
The cheapest Mac Mini and iPad would work just fine for this, as you don't need much storage space, much RAM or whatever.
The entire system (audio interface, MIDI controller and a decent case included) would set you short not much more than around €2,000, then you'd had to add software to it, but given that MainStage comes with all Logic FX already, you'd likely only need that and a decent amp suite, such as S-Gear or so. Let's say with another 200 you'd be good to go for a start.
Such a setup would be incredibly powerful and it'd also allow you to add things as you need them, rather than waiting for the modeler company to add them. Need a better looper? Get Live (or something similar, could even be had for free). Need profiling? Get Tonex. Want luxurious reverbs? Fire up Space Designer (comes with Mainstage) and load some IRs.
Heck, you could even play MIDI synths without a dedicated pickup, just get Jam Origin's MIDI Guitar 3.
Really, that setup would mop the floor with many current modelers.
And having said that, it's in fact an idea I'm keeping in my mind.