I'm placing my bet with Bob. Muse may be a sweet route to HTML article content.
I'd also comment that in the past, with DPS 2014, we would target platforms and had various ways to make discrete content for iPad, iPhone, and everything else (with variations for large/small non-iOS.) But the emphasis and delivery in DPS 2015 falls into phone or tablet, not platform.
The phone/tablet is driven by two factors:
1) The project needs a two top-level system to support
2) separate top-level content structures to customize what's offered to the two device classes and to call appropriate card and layout designs for these classes.
Shift the thought from "platform" to "device class" for DPS 2015.
-Colin