Hasn't anyone seen the big beautiful
Welcome Mat stack has placed outside their doors? What has worked in the past is to do it yourself if you can or go to the 3rd-party developers and make the case for them to invest in the ES related development work you want. This has worked in many cases before, including ones I've been involved in (i.e. YooRecipe with
Saun from the forums too). Go to your favorite Joomla template developers if you can't do it yourself and make the case for them to develop ES themes. If nobody does this, well then there's the opportunity to provide the market need and create your own templates, or pool your resources, get some made, and sell 'em
Seems to me that Mark and the team have done everything imaginable to support a thriving and rich developer community with an
Application generator,
rich API and supporting documentation, an extensive array of custom template positions, Mark making his e-mail and Skype available to assist and nurture Joomla extension developers with assistance in their integration work. They have, probably from "idea stage day 1" planned to be accessible and a beneficial environment for 3rd party's.
One thing I don't know if they've done, which could help, would be to have their marketing resource dedicate more time to 3rd-party "Developer Relations", managing and evangelizing theme and extension development by 3rd parties. Maybe in the future ES will run on non-Joomla platforms too and there will be more prospective template developers to make themes.
But I understand Stack is focusing on two fundamentals: getting the foundation right-sized and rock-solid, keeping customer support informing everything they do.