Apple is gonna make IBM build a cloud base infrastructure with Apple User interface and QA. We are talking very high end costumers, not the typical small or medium corp. No one will be fired for buying Apple and IBM. Google, maybe.
Enterprise Cloud was one Horse race for Microsoft market. Now there are two.
A bit more than a few years. They still have pretty good profits (Windows and Office are still quite popular,) and even if that dried up suddenly and they had zero revenue, they could quite literally live on their cash reserves for a decade.
[edit: downvotes, seriously? I'm just pointing out that Microsoft is not a private company that can do whatever it likes with its cash pile if it is not performing. I guess that is uncomfortable for some reason.]
The problem for Apple is their secrecy and planned three year obsolescence is unattractive at scale for large businesses. A large part of IBM's continued relevance has been from their shift toward solutions leveraging open source as well as providing customers with clear roadmaps.
Without trying to sound too harsh, the problem with Google is that they have a faddish focus, and don't appear to maintain some product offerings once they are past the "look! It's NEW!" phase. If you made the recommendation to switch to Google's systems, would your manager be asking "How long is it going to be there for?". It's a pity. Do you see "enterprise" switching to systems like that? Do you see loads of Chromebooks and Chromeboxes (do they even still make them?) on desks instead of PCs? Honestly?
This is different to Microsoft's strategy where you can still run software from 20 years ago, and some businesses like only investing in software once, instead of an ongoing licensing fee. I do not see Microsoft disappearing quickly, despite how popular web apps are in startup circles; Windows still rules the enterprise desktop.
I myself write software on a Mac but everybody else here has never used a Mac and are flummoxed if presented with its desktop, and typically see Apple products are overpriced.
High end customers would involve large corporations where there would be a need for many PCs traditionally. Although iPads have become popular with BYOD, do most people just accept that it's a great consumer (consuming) device and not marvellous for creation of content? If large corporations were to switch their desktops to Apple machines, do you think the profit margin would increase or decrease?
It just isn't going to happen.