WordPress to Textile Ruby script (I used a Textile plugin for WP). Parses all existing WP categories and tags into discreet list of categories. Finally forces all content to be UTF-8.

wp-xml-import.rb

require 'fileutils'
require 'date'
require 'yaml'
require 'rexml/document'
include REXML


doc = Document.new File.new(ARGV[0])

FileUtils.mkdir_p "_posts"

doc.elements.each("rss/channel/item[wp:status = 'publish' and wp:post_type = 'post']") do |e|
    post = e.elements
    slug = post['wp:post_name'].text
    date = DateTime.parse(post['wp:post_date'].text)
    name = "%02d-%02d-%02d-%s.markdown" % [date.year, date.month, date.day, slug]
    date_string = date.year.to_s + "-" + date.month.to_s + '-' + date.day.to_s
    
    # clean up years of category randomness in one fell swoop. 
    case post['category'].text
    when "diversions", 
         "elsewhere", 
         "family", 
         "health", 
         "life", 
         "meme", 
         "nerdliness", 
         "photography", 
         "random", 
         "relationships", 
         "social issues"
      category_string = post['category'].text
      link_string = false
    when "links"
      category_string = post['category'].text
      link_string = true
    else
      category_string = "life"
      link_string = false
    end

    content_text = post['content:encoded'].text
    
    content = content_text.encode("UTF-8")

    # convert <code></code> blocks to {% codeblock %}{% encodebloc %}
    #content = content.gsub(/<code>(.*?)<\/code>/, '`\1`')
    content = content.gsub(/<code>/, '{% codeblock %}')
    content = content.gsub(/<\/code>/, '{% endcodeblock %}')

    # convert <pre></pre> blocks to {% codeblock %}{% encodebloc %}
    #content = content.gsub(/<pre lang="([^"]*)">(.*?)<\/pre>/m, '`\1`')
    content = content.gsub(/<pre>/, '{% codeblock %}')
    content = content.gsub(/<pre lang="([^"]*)">/, '{% codeblock %}')
    content = content.gsub(/<\/pre>/m, '{% endcodeblock %}')
    
    
    (1..3).each do |i|
        content = content.gsub(/<h#{i}>([^<]*)<\/h#{i}>/, ('#'*i) + ' \1')
    end

    puts "Converting: #{name}"

    data = {
        'layout' => 'post',
        'title' => post['title'].text,
        'date' => date_string,
        'comments' => true,
        'categories' => category_string,
        'link' => link_string
     }.delete_if { |k,v| v.nil? || v == ''}.to_yaml

     File.open("_posts/#{name}", "w") do |f|
         f.puts data
         f.puts "---"
         f.puts content
     end
 
end