Yes, and no, I think.
The Adobe name is a big recommender -- pubs have insisted on using PDF for e-books even though it's poorly suited for that
purpose. If DE were to become the de-facto standard for e-books, then the fact that it's "another" format wouldn't be all that big a burden. This thing could (should, really) replace PDF entirely for e-books, so it'd be a one for one swap.
Also, consider what this might mean for ConnStore books: Perhaps Sony might start offering their books in DE format, rather than BBeB, which would take a second format off the table.
A fella can dream, right?