How about something like this?

diff -r 6ce2da9aa1c7 hgext/interhg.py
--- a/hgext/interhg.py  Sun Aug 26 01:04:15 2007 +0900
+++ b/hgext/interhg.py  Sun Aug 26 01:12:07 2007 +0900
@@ -27,19 +27,19 @@ from mercurial.hgweb import hgweb_mod
 from mercurial.hgweb import hgweb_mod
 from mercurial import templater

-orig_escape = templater.common_filters["escape"]
+orig_decorate = templater.common_filters["decorate"]

 interhg_table = []

-def interhg_escape(x):
-    escstr = orig_escape(x)
+def interhg_decorate(x):
+    escstr = orig_decorate(x)
     for pat in interhg_table:
         regexp = pat[0]
         format = pat[1]
         escstr = regexp.sub(format, escstr)
     return escstr

-templater.common_filters["escape"] = interhg_escape
+templater.common_filters["decorate"] = interhg_decorate

 orig_refresh = hgweb_mod.hgweb.refresh

diff -r 6ce2da9aa1c7 mercurial/templater.py
--- a/mercurial/templater.py    Sun Aug 26 01:04:15 2007 +0900
+++ b/mercurial/templater.py    Sun Aug 26 01:12:07 2007 +0900
@@ -260,6 +260,7 @@ common_filters = {
     "domain": domain,
     "email": email,
     "escape": lambda x: cgi.escape(x, True),
+    "decorate": lambda x: x,
     "fill68": lambda x: fill(x, width=68),
     "fill76": lambda x: fill(x, width=76),
     "firstline": firstline,
diff -r 6ce2da9aa1c7 templates/changelogentry.tmpl
--- a/templates/changelogentry.tmpl     Sun Aug 26 01:04:15 2007 +0900
+++ b/templates/changelogentry.tmpl     Sun Aug 26 01:12:07 2007 +0900
@@ -1,7 +1,7 @@
 <table class="logEntry parity#parity#">
  <tr>
   <th class="age">#date|age# ago:</th>
-  <th class="firstline">#desc|strip|firstline|escape#</th>
+  <th class="firstline">#desc|strip|firstline|escape|decorate#</th>
  </tr>
  <tr>
   <th class="revision">changeset #rev#:</th>
diff -r 6ce2da9aa1c7 templates/changeset.tmpl
--- a/templates/changeset.tmpl  Sun Aug 26 01:04:15 2007 +0900
+++ b/templates/changeset.tmpl  Sun Aug 26 01:12:07 2007 +0900
@@ -34,7 +34,7 @@
  <td class="files">#files#</td></tr>
 <tr>
  <th class="description">description:</th>
- <td class="description">#desc|strip|escape|addbreaks#</td>
+ <td class="description">#desc|strip|escape|decorate|addbreaks#</td>
 </tr>
 </table>