Junokaii (although I'd recommend not adding me because I'm on literally like... once every month or two)
We have carpet in the sense of wool.
Perhaps this could be a suggestion for creative, but maybe not.
But what I'm proposing is carpet, that takes the pattern of normal building blocks, say brick, stone, perhaps even grass.
I say this because.. I love playing at night, and.. every once in a while, I think to myself "I wouldn't mind having my house appear brighter without having to put torches everywhere or glowstone everywhere".
I say this because you can put glowstone down, and put carpet on top, and maintain the same level of brightness without having the look of glowstone everywhere. I used this in one of my parking lots i build for my amusement park, so I could give it an appearance of "bright at night with only a few street lamps (which were just fence posts, and glowstone hanging from them)". So it can have the appearance of a more realistic parking lot, because.. If a parking lot needed that much lighting at night to appear decent... it would look like daylight all the time.
This would be very beneficial for building specific styles of houses, say fairytale kind of houses, or just houses you don't want glowstone or torches on.
I've suggested tiles before, which was basically a stone/wood plank version of carpet, as well as a pile of sand/gravel to do the same basic thing with sand/gravel (4 or 9 piles of sand/gravel = 1 sand/gravel block, placing a 'pile of sand creates the respective 'carpet' layer and collecting it goes back to a pile when as an item in inventory...similar to snow and snowballs).
Although, I didn't have anything for grass blocks, mycelium blocks, dirt blocks, dry tilled dirt, damp/rich tilled dirt, or the ores (iron, diamond, emerald, lapis lazuli, gold, etc). Nor anything for chiseled/cracked/mossy/etc...
But I'd be ok with a 'carpet' or 'tile' for every block... it would just require a few more block ID's for each set of 16 sub-types.