Check your routes for nested resources — :name_prefix isn’t blank by default anymore. Now it’s set to the singular of the parent resource. You can explicitly make that blank, use some find-and-replace regex-fu to fix your url helpers, and even get rid of url helpers altogether from your link_tos and form_fors.
Not necessarily essential, but it’s nice to replace the old rhtml extensions for the shiny new html.erb. This bash one-liner should do the trick: for i in `find . -type f -name "*.rhtml" | xargs`; do svn mv $i `echo $i|sed 's/rhtml/html.erb/'`; done
