At the moment beds are used to set spawn but not skip the night. I don't know whether you guy plan to add that feature but if you did it would still feel pointless, as the mobs aren't affected by the day (as far as I can tell). personally I like this as it's a change from the overworld, but I find that using a bed merely to set spawn, pulls you away from the beautifully crafted atmosphere you devs have created. I don't know whether you guys have a plan for it, but have you considered creating a second use for sleep? I though a interesting mechanic would be insanity / strange thoughts. This would add a meter which would increase slowly ( increasing faster in creepy places i.e. fog, caves) in till it reached certain levels, at which the player gains affects such as mining fatigue, slowness and blindness. The solution to the high insanity is to go to sleep, but the higher the player's insanity the more lightly they are to get a vision / nightmare. ether the get a cut scene of the Prime Wight or, in maybe an extreme case, be transported to an nightmare dimension. This could fit in well with the "it's them." lore scrap.
I think their a lot you can do with it and I hope sleep can be more than skipping the night.