Why do you think that Apple will enter the cloud? Apple hasn't been a real contender in servers for a decade, and it seems like their strength lies more in the design than in raw technical capabilities.
Great question. Apple has a long history on building on the shoulders of giants....and then building their own giant.
Further, they also have a long history of playing suppliers against each other in order to get the best terms.
Finally, Apple occasionally works hard to move away from companies it fights with - Adobe and Qualcomm are two notable ones there, as are the social media firms like Facebook.
As for evidence, I’d offer up this report on future data center spending that they are planning. You don’t have as many data centers and add to it in this magnitude without having a solid strategy.
Give it 2 years, 4 tops.