RMagick not maintained any more?

At the RMagick repo on Github, a message was uploaded yesterday saying the main author cannot continue to maintain the project, and is looking for new people to take over. (I would certainly crash it were I to ever 开发者_运维百科attempt such a job!). You can see their readme here: http://github.com/rmagick/rmagick.

In your opinion, where should a Rails 3 / Heroku / S3 app go, given that it is trying to use Paperclip for file uploads?

I think you are asking about whether to use RMagick or another alternative such as ImageScience. Is that correct? You don't actually need any of those libraries: Paperclip doesn't require them as long as the ImageMagick binaries are available on the app servers.