Possible Apple's side: App revenues may not make for a sizable part of their revenues as of now but they are expecting a humongous growth in both - iOS devices

Possible Apple's side: App revenues may not make for a sizable part of their revenues as of now but they are expecting a humongous growth in both - iOS devices sales and Apps sales (and hence In-Apps sales). They feel the need to get in right now or before it's too late. They might also be contemplating Apple Television and more iOS based form factors. This can be huge.