I am waiting for this as well. I have not been told this, but I hopeing that we can do this when they complete the templating system for engage publish. Maybe even use a token [Thumbnail] to use the image inside our article.
The Simple Gallery integration has been kind of a disapointment. It is very dificult to manage your own codebase and try to maintain compatibility with someone elses and try to keep them both up to date.
I personally would like to see engage add a simple lightbox photo gallery of their own to engage publish.
What would be cool is also using those images in your article using tokens such as [IMAGE3]. now that would realy be nice and alow you to easily upload photos that go with your story and offer the ability to easily layout your images in your news article or blog.
This module is great now, but I believe that would push this module into elite status.