Carnegie Hall~when it rains it pours

Our choir has been invited to sing in Carnegie Hall once again in May of 2009. I guess I know what I am saving my money for next year. We would be singing Brahms Requiem under the baton of John Rutter himself. This is amazing to me, since we have sung many pieces that have been arranged by him in our choir. How amazing is this?
In the same week, our director received a second invitation from Lex de Azevedo to sing with his choir in a piece he has composed called Alleluia, in March of 2009. It was just announced and he told us to think about it. But the consensus was two things. First it would be hard to perform two such hard things so close to one another, second, our director says, our Spring Concert is always at that time, and to skip it would hurt the audience if we didn't remain consistent.