You want SlideML? OK:

#! /usr/bin/python
import re
from xml.dom.minidom import parse
f = open('script.js')
s = f.read();
l = re.findall ('\'([^\']+)\'\s+\+s\(\)\+\s+\"([^\"]+)\"', s)
print open('slideml.txt').read()
for i in l:
    file = i[0]
    title = i[1]
    dom = parse(file)
    body = dom.getElementsByTagName('body')[0].toxml()
    body = re.sub ('^<body[^>]+>', '', body);
    body = re.sub ('</body>$', '', body);
    print '''
        <s:slide s:id="%s">
        <s:title>%s</s:title>
        <s:content>
        %s
        </s:content>
        </s:slide>
   ''' % (file,title,body)
print '</s:slideset>'

Generating SlideML or any other format isn't the problem. The problem is that emacs is still the best way to write the XHTML to fill this hole:

<s:content> INSERT YOUR CONTENT HERE </s:content>

And normal humans don't use emacs.