One common issue with projects that do use some kind of automated formatting (such as Geoserver and Geotools) is that formatters (jalopy) do use the platform native eol when reformatting files. If files do not have the svn:eol-style=native property, each reformat on different platform will change EOL, making diffs useless.
Subversion folks suggest to add precommit hooks that disallow commit if certain properties are not set on files.
It would be really nice if codehaus allowed project admin to set up this kind of precommit hook.