g1smd - 10:35 pm on Mar 22, 2013 (gmt 0)
This looks OK.
RewriteRule ^en/(.*)$ http://www.example.com/$1 [R=301,L]
I would make two minor changes.
RewriteRule ^en/(.*) http://www.example.com/$1 [R=301,NC,L]
Since .* is greedy, the $ isn't needed.
I'd probably also redirect stray requests for /En/, /eN/ and /EN/ using the [NC] flag.