Blaise Aguera y Arcas and Paul Needham concluded that Gutenberg did invent movable type, but his method of creating or casting each letter was different to the way we've always thought. They hypothesise as to the actual method used.
Paul and Blaise's findings suggest that the development of the printing process was more gradual than previously thought. This helps to explain why Gutenberg needed so much money to produce this enormous book. Mistakes in the production process are expensive.
Their working hypothesis on how Gutenberg created type is that a temporary mould was created, one letter cast and the process of taking the letter out of the mould disturbed the surface. So the same mould would have had to be recreated to make the second letter.
Paul and Blaise are continuing to use the same system of analysis to try to establish who did invent the punch and matrix. Their hunch is that it was likely to have occurred in the 1470s in Italy. They have a printer in mind but want to set about proving it before naming names.