As founder of openrev.org, a platform to share and discuss research papers openly (or privately), I am very pleased with this announcement. It is more than just baby steps towards an open, scientific communication system.
In physics we do already have that with the arxiv.org (though there are no public discussions) but it works darn well in my sub-field and others. We cannot wait for most other disciplines to have an epiphany. So grant agencies forcing publishers AND authors to open access their material will bring us a huge step forward towards solving the most challenging problems of our time.