Ardian - it is already common-place and many 'traditional' journals now offer an open access option. Open Access journals are a good thing (apart from if they are predatory). It is just a different business model of publishing and allows choice. Most 'new' journals, I predict, will favour being open access - so we will see a gradual rise in their numbers over time. As funding bodies start to more readily accept open access fees as part of grant applications - this will also drive the model.
it is useful. Open Access (OA) publications reduce permission requirements and eliminate price barriers for readers. OA allows access for researchers, teachers, journalists, policy makers and the general public without a subscription. Many studies demonstrate that OA literature receives more citations than subscription publications.
It is very interesting and promising that most people think of open access in a positive way. I think that academic work that is freely available to anyone would increase also the quality, because it will be also freely available to criticism.