(a) allowing upper case characters in the pagenames
(b) make the search for pagenames case insensitive
(c) sort lists in natural order with a and A followed by b and B followed by v and C ...
For a crude solution/prototype see http://forum.dokuwiki.org/thread/5417
To preserve the current behaviour, a parameter could be used to decide if upper case should be converted to lower case, i.e. if the file system needs to avoid uper case characters.