Denis2

+1
Having a feature like this (and/or some sort of standalone layer presets) would be really helpful when exporting multiple versions of a logo or illustration. Sometimes I need to hide all my fill colors to export a black and white version. Being able to turn color/fill layers on and off without having to do it manually through 50+ layers and multiple groups each time would be a HUGE time saver.

+1
I think this should be a function of the export persona (for all apps). Where you can add slices for the whole document, which store the current visibility of the objects.

I'm missing this functionality, too. I would be really helpfull if it was marked for each slice which layers are visible. Something like "layer compositions" in Photoshop. Therefore it should be possible to use more than one slice per layer.
For example, I have to design cards for a board game. Each part is to be punched out of paper and need a bleeding. The clients wants to see the design as it looks after punching (without the bleed). Thus I export two versions: the complete one with bleeding and one as it looks later when used in the game. Or most parts of a cards design are the same for lez's say 5 cards, but the background changes.
It's quite anoying to switch the layer visibility for each export as there are often 40 and more cards to export. Each variation of the design leads to a new export round. It would be very helpfull if it was adjusted once which layers should be visible per slice and after that one could export all cards in one rush.

It would be very useful if the export persona allowed us to choose what layers were exported for each slice.
I do complicated graphs that build up from simpler ideas. So it is useful to put the basic graph on one layer, some enhancements on another layer, and perhaps point out some specific features on a third layer. I then want to export this as three separate images: Just layer 1, Layers 1+2, and Layers 1+3. At the moment the only way I've found to do this is to manually change the visibility of the layers and the name of the exported file and then export one file. This process needs to be repeated three times in my example.
I can also imagine that icon designers would find this useful. They could have a layer with the basic icon and then other layers with overlays (check marks, or plusses etc). If there was the possibility of selecting which layers were visible for each slice they could set up batch exports for these.

+1
I really didn't need slices at all in my projects so far.
However, what I always need is layer states.
I use Photo and Designer for architecture and turning on and off layers allows me to show alternative versions of the spaces. Different colors, different objects, different lighting... All images should be the same size, but featuring different stuff which is usually organized through layers. As we evolve the project these layers evolve, so having to repeat all the process of exporting and naming each new version of the image is tedious.