XML-schema 1.1 - conditional occurrence of child elements

Are there any plans to implement conditional occurrence of subelements
in XML-Schema 1.1 ?

What I mean is e.g. that the occurrence (or number of occurences) of a
subelement is dependent on the value of e.g. an attribute.

For example:
<element1 hasSubelement="Yes">
  <subelement></subelement>
</element1>

<element1 hasSubelement="No">
</element1>

If there are plans for this, can you already reveal how this is
envisaged to be implemented in XML-Schema 1.1?

I ask because we are currently further developing an international
XML-based standard in the healthcare sector.
We want to have conditional occurrence of subelements anyway (at the
moment tailored-written software has to check), so we want to have the
XML-Schema for it as close as possible to XML-Schema 1.1

Many thanks in advance

Jozef

Jozef Aerts
XML4Pharma