I think the game needs more lighting options. I feel like a partial solution comes from creating more diversity in preexisting blocks. I think we should be able to refine glowstone, in one way to perhaps smelt it into smooth glowstone, which has already been suggested, but to also be able to make both versions (normal glowstone and smooth) into slabs. These would put off maybe 3/4s as much light as a full block and allow for some interesting builds, but you would also be able to recombination them into better looking full blocks much like the chiseled stone brick block.
I also think any of the refined glowstone blocks should be dyeable, to create more lighting and color options. I think these would be a few good first steps to improve the lighting situation in Minecraft.