xsl:if and XPath problems with test

[Tim Crook]

Using an expression like
<xsl:when test=".[(@name='Occurrence')]">
...
</xsl:when>

produces the error:
Error [code:201] [URI:file://...] [line:...] [node:attribute 'test'] 
  wrong expression syntax

When will Sablotron support the XPath ".[ ... ]" format?