It is highly likely that the first adopters of the MPL will be the major European airlines that currently run their own cadet training schemes - airlines like Lufthansa, for example. Such airlines are very unlikely to accept a lower standard of cadet than they do currently. It's my understanding that it is airlines such as these that have driven the development of the MPL, as they feel that the traditional training syllabus is getting further and further detached from the requirements of flying modern airliners.
As has been explained earlier in this thread, the MPL is very unlikely to be a cheap option. The number of hours required in highly-capable and expensive simulators is likely to make the cost comparable to, or even higher than, the current procedure. While it is true that some of the danger will be removed (this is a bad thing?!), I don't perceive the death rate among airline wannabes is so high as to be a significant factor in the selection process!
As in all new things, there will be early adopters, late adopters and Luddites. The early adopters will have to iron out the problems that will undoubtedly be discovered with experience - experience which the later adopters will bvenefit from. For the Luddites, the traditional route will still be available.