> The problem is I need the http://purl.org/rss/1.0/ xmlns declaration to 
> appear on the root element instead of on the channel element.

If you removed
exclude-result-prefixes="rss1" 

the xmlns would appear on the document element, but you'd also get
xmlns:rssl, but that (probably?) does not matter?

$ saxon8 ns1.xml ns1.xsl
<?xml version="1.0" encoding="UTF-8"?>
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
         xmlns:dc="http://purl.org/dc/elements/1.1/"
         xmlns:rss1="http://purl.org/rss/1.0/"
         xmlns="http://purl.org/rss/1.0/">
   <channel>fffffff</channel>
</rdf:RDF>


Alternatively you can not declare the rssl prefix and instead make that
the xpath default namespace (so you can select elements using that
namespace) and use a prefix for your test namespace, and prefix teh
match on n, something like:


<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="2.0" xmlns="http://purl.org/rss/1.0/" 
xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" 
xmlns:xsl="http://www.w3.org/1999/XSL/Transform" 
xmlns:dc="http://purl.org/dc/elements/1.1/" 
xpath-default-namespace="http://purl.org/rss/1.0/"
xmlns:test="http://www.test.com"
exclude-result-prefixes="test"
>


	<xsl:output indent="yes" method="xml"/>

	<xsl:template match="test:n" >
		<rdf:RDF xmlns="http://purl.org/rss/1.0/" 
xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" >
			<channel>fffffff</channel>
		</rdf:RDF>
	</xsl:template>

</xsl:stylesheet>

$ saxon8 ns1.xml ns1.xsl
<?xml version="1.0" encoding="UTF-8"?>
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
         xmlns:dc="http://purl.org/dc/elements/1.1/"
         xmlns="http://purl.org/rss/1.0/">
   <channel>fffffff</channel>
</rdf:RDF>



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