Test page I used to check if it was working:
http://www.mediawiki.org/wiki/User:Simetrical/Id_test
I guess we'll have to wait a year or two to deploy this by default,
unless a workaround for the Opera < 10.50 problem can be found.
* Should we allow a broader set of characters in id attributes, per HTML5? If
* not, use only HTML 4-compatible IDs. This option is for testing -- when the
* functionality is ready, it will be on by default with no option.
+ *
+ * Currently this appears to work fine in Chrome 4 and 5, Firefox 3.5 and 3.6, IE6
+ * and 8, and Opera 10.50, but it fails in Opera 10.10: Unicode IDs don't seem
+ * to work as anchors. So not quite ready for general use yet.
*/
$wgExperimentalHtmlIds = false;