I would imagine that they could get the cost down and the speed up but I wouldn't imagine that the coverage would improve much if they continue to use short rea

I would imagine that they could get the cost down and the speed up but I wouldn't imagine that the coverage would improve much if they continue to use short reads - i.e. small ~32 base bits of DNA. As I understand it, there's enough repetition and duplication in the genome that many of these little lengths are going to be identical: AAAA...AAAA or GGGAGGGA...GGGA etc. and that these little strips will match in many different places when placed alongside a fully assembled reference genome. They will also match and overlap a lot with each other. This means that you can't tell where they're supposed to go when you try to re-assemble your collection of little bits into a complete sequence. This means that you're always going to be left with a collection of bits left over that you have no way of placing into the sequence, hence less than 100% coverage. I guess you would need to be using reads long enough to ensure that each of your fragments was unique to get 100% coverage.