Trying again (bad connection from the cottage). The Maps For HTML Community Group is working on pretty much this concept. We would love contributions from everyone here. We have published a custom element here, which would be great for you to check out for yourself https://www.webcomponents.org/element/Maps4HTML/Web-Map-Custom-Element. We are developing MapML, or Map Markup Language as a way of allowing mashups using simple URLs. There is lots of potential.

Final note I think the map element is actually a good choice as it would enable progressive enhancement of the existing map element for older browsers (see blog post here for a demonstration of that ideahttp://maps4html.github.io/Web-Map-Custom-Element/blog/progressive-web-maps.html)