The AM Forum

http://www.synthtopia.com/content/2015/01/29/korg-noritake-introduce-futuristic-nutube-vacuum-tubes/

Interesting.

FEELEEP

Looks very good.

The main issue may be in the cathode... not much surface area, but neither did the nuvistor...

                                   _-_-

VFD have already been used by hobbyists as Triode amplifiers. Merely a refinement of the idea into something cheap to mass produce and re-designed for the purpose. So if the anodes will retain the fluorescent material that could be additionally interesting as long as it does not make noise. The Knifonium is a newly made tube type synthesizer (musical instrument) usign regular tubes. These tubes have obvious applications. I hope that several types will be made, and sold cheap as traditional tubes.

The pictured example appears to be a dual triode, mu = 300,  Heh heh. If the pins are on 1/10th inch or so centers, size looks to be not much bigger than a 48 pin dip.  Fun.

A pair in cascode would yield a very high mu stereo preamp stage. Seriously I'll bet the mu per triode is between 100 and 200.  Only limitation might be the dynamic range at low Ebb voltages. At least the cascode circuit would stack this requirement.

What's next?  Plate modulation on an SMT chip!?

There are many features in the picture one will understand if one knows VFDs.
Here are facts about VFDs from the manufacturer Noritake who makes the item in the OP.
http://www.noritake-elec.com/vfd_operation.html

I suspect you would need two of them. It looks like the device in the picture is a directly heated dual triode with one side of the filament in common.