I believe they are guilty and their pleas confirm that. Not only that but Echols attorney withdrew any further DNA testing. So, we should not hold our breath on anything coming out of that.
Their pleas confirm that they maintain their innocence, too. I won't go into why they accepted the Alford plea again, as it has been discussed ad nauseum. As to DNA, all DNA testing has been completed. Echols' attorney withdrew the Federal petition (habeas, IIRC), which withdrew the DNA testing requests, also. Don't forget that Damien has always said, "Test everything!" I believe that there will never be any evidence of their guilt found, because they are, in fact, innocent.
Besides, they were never convicted on DNA evidence.
However, there is an Arkansas statute that allows a convicted person to test DNA when additional information is found. At the ASSC Oral Arguments, the State argued that the statute only referred to evidence of guilt. However, the Justices ruled that "all" really did mean all, and the testing proceeded. Yes, they were not convicted on DNA evidence (it was in its infancy at the time, anyway), but they could have been exonerated with it. Since none of their DNA has been found, I'd say that DNA was, if not incontrovertible proof of their innocence, at least an indication of their innocence.
If given a new trial I have no doubt that DNA evidence would come into play, but it would not be only the DNA the defense has so carefully selected, but what the prosecutor would bring forth, PLUS the fiber evidence.