I'd known the Enola Gay had been assembled because the tail of the bird can quite clearly be seen in this picture, which has been on the NASM website for about a month now.
The progress of the Enola Gay has been something I've been fortunate enough to witness first-hand, if only briefly. During my very first visit to the DC area in 1993 myself, my brother, and a friend visited* the now-closed Paul Garber Storage Facility in Suitland Maryland. The Enola Gay had just started its restoration project, and was in several large (and many thousand small) pieces all over several different workshops. The entire plane was an oxidized gray, the fuselage looked like a giant chainlink fencepost that'd been left in the weather a few years. Only a few small spots had been polished up, I guess just as a way to test things out.
When they finally put the finished nosepiece (all that they could fit) on display "downtown" five years later, the transformation was staggering. What had been a sad, bedraggled bonyard refugee was now a gleaming trophy. It even smelled new! The detail of the restoration was just amazing.
The Air Force Museum in Dayton will literally let you walk up and touch Bock's Car. I can only hope the Enola Gay display will at least let you get closer than the downtown museum ever could.
Oh, and the Concorde is already inside too. I caught this partial exchange a few weeks ago on my radio scanner:
Controller: I'll bet you're wondering about that Air France at the end of 1 Right
Pilot: Ummm, yeah, what's up with that?
Controller [laughing]: They're moving it into the new Smithsonian museum today. You'll see it just beyond 1 Left as you depart.