In this case, the aircraft was positively identified from markings on the wreckage, so we know that the plane he took off in crashed on that ridge between Mammoth Mountain and the Minarets.
The missing piece is positive I.D. on any human remains. As shredded as the aircraft was, Fossett certainly did not survive but without identifiable remains, there isn't final closure.
One would hope that this latest discovery provides that closure, once the bones are examined and tested for DNA.
Steve's family deserve no less than to know that he did, indeed, perish in that crash.
(If it sounds like I have a personal interest in this case, that is true, if even that my one meeting with Steve was a brief but very cordial conversation about Mt. Ritter at a Washington University alumni event and later that he graciously sent my son a congratulatory letter when Nathan completed his Eagle Scout rank. As you may know, Steve was an Eagle Scout himself and president of the Eagle Scout Association, so his willingness to congratulate a fellow Eagle Scout was understandable but he did, in fact, take the time to respond. Definitely a class act in every sense of the word. Yeah, it's personal...guilty as charged, Your Honor.)
(No offense taken, none intended...just a bit of explanation.)