Early indications, including personal communication with ReadCube personnel, are that Magic Citations (now called SmartCite) will no longer integrate with Scrivener. The new Papers app will only work with Microsoft Word. Bibliography formatting is not an issue for me. The biggest loss is the ability to add citations on the fly in Scrivener without interupting my writing flow.The news of this impending feature loss (along with the announcement of an annual fee) had me scrambling to invesitgate my options for citation managers. During my search, I came across this Wikipedia article, Comparison of Reference Management Software with a great table that collates the majority of software out there.My needs are the following:

Ability to organize and search through metadata and pdfs
Integrated citation insertion with Scrivener and Ulysses
Ability to insert citations while writing on an iOS device
Ability to annotate PDFs and export each comment individually appended with the article's metadata
Ability to export metadata (to enable my workflows for sense-making and export of annotations)

I looked at the following:

No product currently fills the void left by Papers, although the consensus of users (both those seeking alternatives to Papers and those who are being forced to leave Sente) seems to be to move to Bookends. I tried the demo version of Bookends and was not impressed. I am waiting impatiently for the release of ReadCube Papers. If the majority of features are retained, I will likely bite the bullet and pay the annual fee. I plan to figure out a work-around to add citations to Scrivener / Ulysses.I'd be interested in hearing your plans / thoughts on academic citation managers.