I believe it is not beyond the whit of man to get this thing certificated. If it needs another door or 2, then it shall have them. Airbus will do, I'm sure, whatever work is necessary to make the A380 pass - both in the U.S. and Europe (they already did with the A346 - a redesign was worked out).
So here's the really scarey part - if the TC is permitted to be the same by the FAA, then no retesting to the latest standards. So a 737-800 with winglets (circa 1999 or so) is certificated to the same standard as a 737-100 (circa 1965 or so). Now that worries me just a tad given what we've learned in the interim. I do believe that the much lauded "new wing" of the 737NG hasn't been fatigue tested to today's standards even though it is a "new design" (Inside quote marks are what Boeing are claiming - new wing and new design). That leads me to believe either:
1) it ain't new
or
2) it ain't up to the latest standards
Hmmm.