We'll respond shortly.
No one has run into this specifically, but a few people said to make sure you’re mocking out Paperclip.
It was mentioned that Artifice is good for Selenium tests while Fakeweb and Webmock are good for rSpec tests. VCR’s got some fans as well. Sounds like you can’t go all that wrong whatever you choose.
GoGaRuCo – This year it will be September 16th & 17th. A call for proposals will be going out sometime in the near future.
Unicorn – it turns out that Unicorn doesn’t reopen logs after a log rotation unless the path to the log in Unicorn is absolute – so don’t use relative paths!