Well, you have what you asked for!

• More functionality: support for regexps, grouping, date manipulating functions, collations etc.

But also, interoperability with other specs:

• XML Schema simple types
• XML Query

But XSLT 2.0 is not that complicated:

• A lot of the added complexity comes with the (optional) type information
• Functions and Operators are a library
• No fundamental change in processing or data model
• Code can be much shorter in some cases:

  <foo>
    <xsl:attribute name="bar">
      <xsl:choose>
        <xsl:when test="baz=1">baz1</xsl:when>
        <xsl:otherwise>baz2</xsl:otherwise>
      </xsl:choose>
    </xsl:attribute>
  </foo>

  Can be shortened to:

  <foo bar="{if (baz=1) baz1 else baz2}"/>