It’s up!
http://www.sidefx.com/index.php?option=com_content&task=view&id=2604&Itemid=66
“The Houdini Engine now includes access to all of the new Houdini 13 features such as finite elements, enhanced Bullet, new particle tools and a feature-rich Find Shortest Path tool. The plug-ins were written with the recently updated Houdini Engine API 1.5 which adds texture baking, volume support, and more. Volume support is especially notable because it lets artists work with assets built using Pyro and Cloud FX tools in the Houdini Engine.”