I maintain the link-grammar natural language parser, and need editline, not readline, for licensing reasons. I noticed recently that editline does not work with cut-n-paste of UTF8 Russian text (link-grammar supports arabic, persian, german, and now russian) so getting a usable UTF8-capable editline would be great.
A utf8-enabled version of libedit seems to be here: http://www.thrysoee.dk/editline/