The tidy package which is in fink is rather old, and the project has been revived and has come out with a new 5.0.0 release suitable for distribution with fink. It's currently also distributed via brew and Macports, and it supports HTML5.
See https://github.com/htacg/tidy-html5 for the github project, and http://www.html-tidy.org/ for the web site, and https://github.com/htacg/tidy-html5/issues/272 for the specific issue to track this request.
There is a known dependency that php5-tidy depends on the old libtidy-0.99.0-shlibs.
I just added libtidy5/libtidy5-shlibs to cvs. The binary is still called 'tidy'.