CM:  You're right but 6.Nf7+ Kc8 7.Qxe8+ Bxe8 8.Rd8# the knight is blocking the other bishop.

No, I agree with IssacB, 5. ... Bd7 looks better. I've been lookng at it for a while, I guess he didn't see it ingame. It's not mate because that bishop is no longer on c8, WTHarvey.

The queen doesn't have to take after Nxe7 (If so, it's a mate in 10).  At this point, ...Qd6 or ...Qd4 (a mate in 14).  It wins, to be sure but when, is uncertain. 

If Black plays 5...Bd7 6.Nf7#

A quicker way to mate. the white knight goes from D5 to E7 the black queen must take the white knight or else white queen goes to G8 and mate. then the white queen goes to G6, there are some variations here, in all of them the queen is dead and the black can resign or mate in a few moves. in the solution above at move #5 why can't the black answer with the black bishop C8 to D7??????

 I think my solution is simpler.