I was thinking more for a music point of view. How many users could Apple win over into the ecosystem just by letting you sync your iTunes library with your Android phone? I'm thinking a lot.
I'm sure that, to Apple, the more relevant question is: How many iOS device users would they lose by letting you sync iTunes library with your Android phone?
I'd guess a lot, but even if that's wrong, it takes hundreds of incremental music sales to offset the loss of just one iPhone sale.