The platform of the day chases technology somewhat, but it's mostly a business-driven cycle: The entrenched winners on the current platform have little incentive to move boldly forward into a new domain where they have little advantage and little to gain by rushing forward.
Competitors face an uphill battle on the current platform, but much greater opportunity by rushing into these new domains and pitching them as an alternative or unambiguous step forward. (When nothing of the sort has ever actually been true.)
So now we roll on to a fight over the mobile platform. The simple analysis would be to assume that one company will again dominate and squeeze the platform. But if we look more closely at the battle over the internet, we see the very interesting fact that no-one won.
When we look to why, it's almost entirely due to the emergence of Open Source as a serious competitor. It became the vehicle whereby underdog competitors and jaded customers could gang up against the favorite to prevent any one company from truly controlling a platform.
That's why Google took the Open-Source route with Android. Not because it's necessary, but because they saw the iPhone coming and they knew that with an Open approach, everyone would help them fight Apple or any other would-be dominant.
(As in other areas, Google's underlying strategy is: we'll do fine as long as we can compete and don't get marginalized by someone else controlling the platform and writing us out.)
So my guess is that no-one will "own" mobile either. There will be some large-ish companies that together dominate much of the space, but it will be more like the MS/Google/Facebook share-split on the net than the MS/Apple split on the desktop. Also, as with the internet, the roster of the major players will be far more fluid.
(I don't buy "the cloud" or "services" as a distinct platform unto themselves. They're just the continued maturation of the last platform, the same way the desktop continued to get better even after the fight over the network was well under-way. They're being pitched as a companion feature in the mobile fight the same as integration to particular desktop software was pitched as a companion feature in the network fight.)
As for the 'next' platform, that tends to be something laying in plain sight while the current cycle thunders on. Something promising but clumsy. Exposed as necessary, but still nascent.
My guess? Personal area networks; specifically to effect less-awkward Augmented Reality and end the proliferation of redundant sensors.
Anyone with a powerful laptop, smartphone and/or tablet has wanted a way to sync session, state or data streams between these devices without waiting on a slower, spotty intermediary. Does each and every device I own need its own (mostly lame) camera? How about one camera on my necklace/ear/glasses and a data stream? How about my phone's GPS stream and net connection gets naturally shared to my tablet?
The clumsy stabs at this so far will pale to the ultimate platform the same way the first forms of the internet pale to the web today.
And the refinement of it, after the PAN fight settles down and everyone starts to look at the next big thing, promises to be truly the stuff of science-fiction.
Wow that was long. Sorry.