I recently asked this question Are there USB-A to USB-C adapters for the Early 2015 MacBook and it was closed as "primarily opinion-based" due to there not being enough detail since it was all rumours then. Now the 12″ Air has been launched, could we re-open it? This is because there's more official detail about it and if not there will be soon.
As it stands, it's both opinion-based and off topic. We are for practical questions about shipping hardware. I would say you can edit to ask more "how to determine how USB-C works and less dependent on Apple releasing a modified MacBook Air in 2015.
The short answer, is no one can order any Apple product with USB C so there's not much benefit to the site to have a speculative discussion question open. If and when hardware is orderable and/or announced with technical details - flag that question for moderator review if you don't have the reputation to cast a reopen vote.
Basically, when you have a hardware purchase dilemma, ask here how to educate yourself to understand the technology directly. Illuminate that core question with the hardware you wish to buy - but make the question about how does one learn to understand [protocol | connector | software | performance benchmarking | etc... ] so that you can make a good decision.
Shopping questions that revolve around price, avaiability, or soft generalizations (e.g. Which MacBook for a developer) get closed as off-topic and/or opinion based.
Cheers and welcome to the site. I look forward to learning about USB C as well.