I wonder what other certifications, degree(s) and experience an employed EA, as compared to a paper ED, will need to have? How hard is it to break into the field once you've got the piece of paper?

I think one reason Microsoft has an EA certification is probably because it might take an architect to draw up the plumbing blueprint to utilize their forthcoming services. And with cloud computing and storage, to be fair, in general, the blueprints do become more complicated, whether you are paying Microsoft for SAAS or Amazon or Google.