I’m not an RSS reader developer any more. But if I were, I’d start looking for an alternative syncing system right now.
Google Reader decimated the market for commercial desktop and web RSS readers, then became the de facto standard for all mobile RSS readers to use as a sync platform… but with an unofficial, unsupported API, on a product that Google doesn’t seem to care much about.
The bad news is that there really isn’t an alternative RSS sync platform that I know of. The good news is that I don’t think there are any significant barriers to creating one, should it become necessary.