Harry C Marks at Curious Rat makes some good points rebutting the silly idea that iTunes in ‘da Cloud lacks a streaming option as some sort of concession to AT&T & Verizon capped data plans. (The thought that Apple gives the tiniest shit about AT&T or Verizon has me chortling).
My take is that Apple sees streaming audio the same way that they see web hosted data (which does not mean web apps as some bloggers learned last week). The entire premise behind iCloud is that your data lives everywhere simultaneously — web, iPhone, desktop — there is no one preferred device. A streaming solution would break that model.