Until an unless you won't tell your exact requirement it will be difficult 
to suggest anything:

What Martin and Michael has suggested works perfectly for me in 2.0. Even 
the below one works for me in 1.0:

<xsl:template match="root">
<xsl:element name="root">
<xsl:copy-of select="@*"/>
<xsl:apply-templates/>
</xsl:element>
</xsl:template>

Are you trying to remove any specific namespace or all of them in root 
element? Please post the sample input and required output.

HTH,
Pankaj Chaturvedi