I personally feel the pain point of password/identity management across different websites, and I'm using LastPass to help. While LastPass's browser integration is great, its UX is... lacking. Mozilla's strategy to associate Firefox browser with identity is IMO awesome and the first sign that it's pioneering vs reacting to Chrome (before this news, I've always viewed Firefox as Chrome's successful but still little brother in terms of features, polish, performance, support, etc.).
BUT (and this is a big "but" I feel), this is contingent with their execution of browser integration. W/O rock solid browser integration with fluid UX, this would just add noise to identity services and cause more consumer confusion.
Ultimately, I'm rooting them on because a) I'm concerned about my security and b) I have too many passwords and c) I'm hella lazy.