Looks like this might work (I'm getting output), but it probably still needs some tuning:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE 
xsl:stylesheet [ <!ENTITY nbsp "&#x00A0;"> ]>
<xsl:stylesheet 
  version="1.0" 
  xmlns:xsl="http://www.w3.org/1999/XSL/Transform" 
  xmlns:msxml="urn:schemas-microsoft-com:xslt"
 
  xmlns:umbraco.library="urn:umbraco.library"
 xmlns:Exslt.ExsltCommon="urn:Exslt.ExsltCommon"
 xmlns:Exslt.ExsltDatesAndTimes="urn:Exslt.ExsltDatesAndTimes"
 xmlns:Exslt.ExsltMath="urn:Exslt.ExsltMath"
 xmlns:Exslt.ExsltRegularExpressions="urn:Exslt.ExsltRegularExpressions"
 xmlns:Exslt.ExsltStrings="urn:Exslt.ExsltStrings"
 xmlns:Exslt.ExsltSets="urn:Exslt.ExsltSets"
 
  exclude-result-prefixes="msxml 
umbraco.library Exslt.ExsltCommon Exslt.ExsltDatesAndTimes 
Exslt.ExsltMath Exslt.ExsltRegularExpressions Exslt.ExsltStrings 
Exslt.ExsltSets ">

<xsl:output
 method="xml" omit-xml-declaration="yes"/>

<xsl:param name="currentPage"/>
<xsl:variable
 name="url" select="concat('http://',umbraco.library:RequestServerVariables('HTTP_HOST'))"
 />
<xsl:variable
 name="maxLevelForSitemap"
 select="10"/>

<xsl:template
 match="/">
<xsl:value-of select="umbraco.library:ChangeContentType('text/xml')"/>
<urlset xmlns="http://www.google.com/schemas/sitemap/0.84">
  <url>  
    <loc>
       <xsl:value-of
 select="$url"/>
    </loc>
<lastmod>
      <xsl:value-of
 select="$currentPage/ancestor-or-self::node
 [@level=1]/@updateDate"
 />+00:00
    </lastmod>  
  
  
  <changefreq>daily</changefreq>
    <priority>0.8</priority>
  </url>

<xsl:call-template
 name="drawNodes">  
<xsl:with-param name="parent" select="$currentPage/ancestor-or-self::* "/>  
</xsl:call-template>
</urlset>
</xsl:template>

<xsl:template
 name="drawNodes">
<xsl:param name="parent"/> 
<xsl:if test="umbraco.library:IsProtected($parent/@id,
 $parent/@path) = 0 or (umbraco.library:IsProtected($parent/@id, 
$parent/@path) = 1 and umbraco.library:IsLoggedOn() = 1)">
<xsl:for-each select="$parent/* 
[string(umbracoNaviHide) != '1' and @level &lt;= 
$maxLevelForSitemap]"> 

<url xmlns="http://www.google.com/schemas/sitemap/0.84">  
<loc>
<xsl:value-of
 select="$url"/><xsl:value-of select="umbraco.library:NiceUrl(@id)"/>
</loc>
<lastmod><xsl:value-of select="@updateDate"
 />+00:00</lastmod>      
<changefreq>Weekly</changefreq>
 <priority>0.5</priority>
</url>

<xsl:if test="count(./* [string(umbracoNaviHide) != '1' and 
@level &lt;= $maxLevelForSitemap]) &gt; 0">   
<xsl:call-template name="drawNodes">    
<xsl:with-param
 name="parent" select="."/>    
</xsl:call-template>  
</xsl:if> 
</xsl:for-each>
</xsl:if>
</xsl:template>
</xsl:stylesheet>

Is it 4.7 compatible? Is it possible to setup priority for a page?

You could set up a a page property to set the priority and output it in the xml, sure

I haven't used 4.7 for production websites yet, so don't know. I don't know think anything has changed regarding xslt though?

is working on a reply...