On the surface, Wednesday's discovery is what investigators have been waiting for -- the first physical piece of evidence since the flight vanished en route to Beijing in March 2014 with 239 people aboard.
Planes are stamped with serial numbers to allow parts to be identified and matched to a specific model and aircraft.
"If the part numbers that are stamped on the pieces of the plane still survive, it literally could be a phone call to Boeing or the parts indices to see if it belongs to a 777. And if it belongs to a 777, it is MH370," said Mary Schiavo, CNN aviation analyst and former inspector general of the U.S. Department of Transportation.
Schiavo points out that there have been only five accidents involving Boeing 777s, and the disappearance of MH370 is the only one where debris hasn't been recovered.
Boeing investigators are confident the debris found on Reunion Island comes from a 777 aircraft because of photos that have been analyzed and a number that corresponds to a 777 component, according to a source close to the investigation.
Investigators from the United States still want to see the debris, believed to be a 777 flaperon, up close to make a final determination, the source said.
Boeing and U.S. government investigators from the National Transportation Safety Board will be given access to the debris once international investigators get it to a lab for examination, the source said.
A component number is not the same as a part number, which is generally much longer.
If the identifying numbers are missing, more tests will need to be conducted on the part to determine its origin.
Australian investigators, heavily involved for some time in the search, said they are looking at the barnacles attached to the part that could allow marine biologists to tell how long it has been floating.
Moving the debris for examination
France and Malaysia will lead the investigation.
The debris will be flown to Toulouse, France, and handed to the French aviation safety bureau BEA, according to Malaysian Prime Minister Najib Razak.
Malaysian investigators should be in Reunion by Friday, he said, and another Malaysian team is going to Toulouse to work with BEA experts.
If it is from MH370, will the main search area move?
Unlikely, analysts say.
The discovery of the potential debris off Reunion Island in the west Indian Ocean is consistent with the route of currents in the region and the time it would take for a piece of metal to be washed thousand of kilometers across a vast ocean, experts said.
"It's possible that it could have drifted that far -- certainly it is possible, especially if air was maintained in that particular piece," said former pilot Les Abend.
Australian Deputy Prime Minister Warren Truss said if the piece is from MH370, it would indicate authorities are searching in "roughly the right place."
The current search is focused deep on the seafloor off Western Australia, along an arc considered by investigators to be the most likely area the plane went down if it turned back toward Malaysia, as indicated by data, and stayed in the air before running out of fuel.
If it's part of the plane, is it more likely the main section will be found?
Truss said no.
He told Australian media Thursday it is "not really going to be all that helpful in pinpointing precisely where the aircraft is."
However, if confirmed, the find is likely to give investigators further belief that other pieces of the plane have been carried by currents to the same region.
Will the search area expand?
If the piece is confirmed to be from MH370, searches are likely to be conducted of surrounding islands.
However, experts are divided as to whether one or more pieces of floating debris will give many clues about the fate of Flight MH370.
"It really is not going to tell us too much about the final moments of the aircraft," said Geoffrey Thomas from AirlineRatings.com
. For that, the flight data recorders -- or so-called black boxes -- are crucial.
However, Tom Ballantyne of Orient Aviation magazine said the condition of the wing could indicate if the plane met a catastrophic end. Charring, for example, could indicate an explosion, he said.
Will debris found near Reunion led to a rethinking of past theories?
Thomas said, if anything, the location of the potential debris confirms modeling from the University of Western Australia that showed material from the plane could wash up around Reunion between 12 to 24 months after the plane's disappearance.
Despite the modeling, no one had been searching in that area, he said, because of the vast nature of the Indian Ocean and the multitude of factors that meant finding anything would be matter of luck and time.
"It was a matter of waiting for something to wash up," he said.
Thomas said, however, if confirmed the find would dispel the conspiracy theories that suggest investigators were searching in the wrong place, or that somehow the plane may have landed safely undetected.