This is definitely a good thing. We run ours from an SVN hook so that all code has to pass the house standard (a modification from PEAR) before it can be committed (this was one of the best decisions I ever made).
Of course, this works best for a new project, where there isn't loads of legacy code to convert to the new standard. One way around this is modify your SVN pre-commit hook to only run new additions to the codesniffer and to ignore modifications. You can do this by adding the line:
$SVNLOOK changed "$REPOS" -t "$TXN" | grep "^A.*\.php " > /dev/null || exit 0
This will exit the hook script if there isn't a new PHP code to parse. Hence all new files will need to obey the standard and you can bring the legacy code up to the standard in your own time.
