"Uncaught exceptions raised anywhere in your application will cause
RAILS_ROOT/public/500.html to be read and shown instead of just the
static “Application error (Rails).” So make it look nice if you aren’t
using it already!"
No more fooling around with rescue_action_in_public is required now.
If you get a 500, you can't be sure your server is really working right. A
500 is a server error so your Rails app might be hosed. It's probably safer
to render an html page than try to rely on the app to do something smart.