Big indicator, leading indicator, of Apple in the enterprise. IT will fall in love with Apple.
No company uses expensive PBX's these days, many companies already moved to mobile phones and IP phones a LONG time ago. Those that use PBX's due so for specific reasons. Cisco and Microsoft are both leaders in enterprise IP phones and Apple coming close to touching that. One area that Apple hasn't figure out yet is meeting room communication systems because its hard to cram a bunch of people around a single iPhone when there are systems design to take in the entire meeting room into consideration and connect numerous participants on one huge screen.
I would even suggest that the idea of a company offering mobile phones to their works is an antiquated concept. A lot of companies are simply giving their workers credit to cover their phone bills if they use their mobile phones for work purposes these days. Handing out "company" phones is a nightmare for most IT workers.
I guess you don't work for a living if you think iPad is great for most "work" purposes. Also I guess you never tried to commission getting an Apple MacBook or Mac Pro as your workstation when IT budgets have been used to "Windows Value" for so many years. Why pay 4 times more for something just to run the same applications? Doesn't make good business sense.
You can use one OS for all purposes, it is called Windows. Surface Pro is better suited for office and home usage because it still runs the business apps necessary for real work, but then can switch over to vapid casual touch apps at home. Microsoft is light years ahead of the curve on this one, provided I care to use one device for home and work, but most people are happy with an iPad for home and a real computer for work.
I think it is clearly arguable that Macs are no more secure than Windows or Android these days, and there just as many security holes found on iPhones, including the frequent and troubling "lock screen" bypass hacks. Claims of greater security come and go like the tide because people only remember what OS had the last security exploit and seem to forget that any other OS also had their turn in the headlines.
Apple and IBM are making a last ditch effort to be relevant in mobile enterprise by latching on to each other. They may be kings in other markets, but are very far behind mobile enterprise productivity.
Yes, Microsoft supporting iOS with Office is a big win, for Microsoft. Apple's "word processor" is a joke compared to Office which is why Apple gives it away.
Also Apple tried to win over IT workers over a decade ago, and Apple has pulled out of every enterprise offering they used to make including their own Rack servers and business software tools. Coming back and trying to make iPad a tool for business is a joke compared to what they used to offer and failed at already. This is Tim Cook trying to grow iPad in a market it was clearly not designed for.