I've heard Leonard Bernstein do it many times. My favorite of his is his "Chichester Psalms" for Chorus and Orchestra. So exciting.
I know Ricky Ian Gordon can do it, and I bet it would sound awesome.
And ALW did it once with "Requiem".
A couple of Broadway composers I would love to hear crossing over to classical:
Adam Guettel (why not?)
Jason Robert Brown (he would sound awesome, and he knows a thing or two about choral arrangements)
Alan Menken (he writes some of the best pieces for orchestra, so why not?)
Michael John LaChiusa (that should definitely work)
Anybody else, or does anyone second mine?
"How could she just suddenly, completely disappear into thin water?" - The Little Mermaid