> I am looking for something like
> 
> =====
> <xsl:variable name="nodename">
>   ... any computation that yields the name of a new element ...
> </xsl:variable>
> 
> <xsl:element name="$nodename">
>  ... anything ...
> </xsl:element>
> =====
> 

You want <xsl:element name="{$nodename}">. If the name is in a namespace,
use

<xsl:element name="{$nodename}" namespace="{$uri}">

Michael Kay
http://www.saxonica.com/