I attended the taping as well. What really surprised me is that everyone was quieter during the performance than your typical Hollywood Bowl Williams concert. At the Bowl, one can't go 5 minutes without someone loudly asking his/her neighbor what movie a piece is from or crinkling some plastic wrapper :/.
^^ Yes, it is. Very much so. A full choir is used and the orchestration is much more lush; gone are the period instruments e.g. the harpischord. It's also (naturally) quite a bit longer. It was definately one of the highlights of the evening in terms of surprises.
I just got back from attending the rehearsal for Williams' concert tonight at the Hollywood Bowl. I thought I'd share a photo I snagged from about midway to the back of the bowl (in the aisle between section D and F). The quality is as good as I could manage from that far back (and zoomed in at 480mm):
(Here's where I was, taken after most everyone left: )
I met Williams at a Costco (yes, Costco). He and Yo-Yo Ma were there for a signing event. Aside from having some liner notes signed, I managed to shake his hand...