The first to market with support for iOS 7 are obviously going to have a huge advantage over other App developers. the SDK being down for every developer without access to alternative platforms for their dev stack are now put back on schedule plus the length of the outage. Again, first to market in such a large market is a huge advantage, providing social and technical momentum, making or breaking careers and enterprises for those who depend on Apple's generous returns. Entire companies can be birthed or go splat due to variables like this. It's a risk they app devs are aware of, but that doesn't mean it isn't a Big Deal.