Bottom line is Apple realizes the Mac's future is about to come to an end so they are "smart" moving into other areas iOS, iPhone, Tablets, TVs (we'll see).
That's why they discontinues X-serve, Logic no updates, Final-Cut nightmare. They have no intentions for the Mac for the long-term future.
Apple will survive without Mac OS, but the companies future all rides on how innovative they can be without Jobs. The iPod market is dying quickly, the iPhone Market is about 50/50, but losing ground to Samsung. The Tablet is doing well, but everyone is entering the market: Google, Microsoft and then there is the Kindle.
In my opinion Apple's future is very uncertain. I also believe their stock price is way overvalued, but people have been betting against Apple since their inception.
I would love for them to continue their success as a non-stock holder. It's just a risky future, especially without Jobs