Your official blog post is inane marketing-speak that has no basis in the reality of the damage Elsevier has done and continues to do to the fabric of science publishing. Mendeley should be ashamed, and you personally should be ashamed for perpetuating this nonsense. Within a year your company will be effectively dismantled and anyone left over who actually cares about open access can start over from scratch. I wish them luck.
There have been detailed discussions about how Mendeley can integrate with parts of Elsevier like Scopus and Science Direct. I don't think they would have gone through all that effort just to bury it. I could be wrong, but I think things are changing at Elsevier and I think bringing us in is part of that.
Not only are they horribly exploitative towards the academics and librarians who by and large both write and purchase what Elsevier publishes, they also ... sponsor arms fairs! whee!