Certainly if browsers integrate annotation natively, it would increase the discoverability of conversation considerably which is of course the point. I persona

Certainly if browsers integrate annotation natively, it would increase the discoverability of conversation considerably which is of course the point. I personally think if that is done it should require the user to purposely choose an annotation service as well. The actual act of inviting the conversation to pages should involve a user choice. See further thoughts on the question of page owner consent-to-be-annotated in another of my replies above.