The "hard problem of explaining conciousness" is discovering all the small biological and neural correlates. It's a hard problem in the sense that finding all the subatomic particles in an atom with a particle accelerator or sequencing the human genome is hard.
On a theoretical level, I think consciousness has already been explained and is not a hard problem unless you are using a hard definition. A state of consciousness is whatever neurons happen to be ON or ACTIVE in an arbitrarily small interval of time. The information held in a system at a current time.
A good example is the phenomena of hemispatial neglect. In this disorder, if a person suffers damage to say the right portion of their parietal lobe, they will not be able to integrate the left side of their world. People will only shave the right side of their face or eat food off the right side of their plate. If asked to draw the times on a clock they will only draw 12 through 6. One part of the brain is not allowed to activate, and the result is a radical change in conciousness, the lack of conciousness of the "left" side of the world. One patient as even stated that he didn't know why they called it neglect, because it implies there's something there that he was ignoring.
Perhaps when people say "conciousness" they are referring to "HUMAN conciousness" and that is a much harder problem. Again, I don't think it is so hard. The unique aspect of human consciousness, as to why we consider it more evolved than other forms of consciousness, can easily be defined as capacity for analogical reasoning. It isn't external tool use, as even crows are quite capable of this. Compared to other intelligent animals, humans are by far the most advanced at analogical reasoning, with bottlenose dolphins and great apes coming in a distant 2nd and third.