The French 'procureur adjoint', during the press conference in France this evening, used the words 'very strong presumption' that the flaperon is from the Malaysian Airlines plane.
As a PP said there was no mention during the press conference of a serial number.
The french journalists immediately analysed this 'caution' in the wording from the 'Procureur adjoint' as being related to the passengers families and the legal context.
The Procureur adjoint named all the people present during todays 'unveiling' of the flaperon- there were many, many representatives there including officials from Singapore and England as well as the usual suspects;
Here's the link to the Press conference (from You tube, quality a bit poor):
https://www.youtube.com/watch?v=TVkqg4xny2U