Nothing is standing still in the world of mobile: neither the OS choices, nor the players, nor the form factors.
The mobile environment has grown and changed remarkably since Apple released its SDK for iOS in 2008. If anything, it is changing faster than ever now. Developers planning for 6 or more months out ought to stay aware of which way the wind is blowing.
New OS entrants
We've written about the new, Linux-based (and other) would-be challengers of iOS and Android: Firefox OS, Ubuntu for Phones, Tizen, Sailfish, and WebOS. If any of them catches on, for developers these dark horses add uncertainty and the likelihood of needing to master new and different development models and environments.
Is Apple "done?"
Apple's stock has been taking a beating lately, largely on the basis of rumors that Cupertino has cut orders for the supplies that will go into iPhones and iPads for the rest of this quarter. While these rumors are debated, there's little argument over the slowing of the iPhone's growth. The phone is losing market share to Android.
More worrying trends are beginning to be discussed. Perhaps it's a matter of kicking a guy while he's down, but trend watchers are starting to say that Apple is over. We're not talking about scientifically valid surveys here, more like conversations with 15-year-old girls.
But consider: parents, grandparents, and (worst of all) teachers have iPhones now. iPhones are for sale at Walmart, the capital of uncool. Kids are saying that the Samsung Galaxy S III phone is way cooler than the iPhone 5, and that Microsoft's Surface trumps the iPad.
That latter assertion sounds odd when contrasted with what looks like the utter failure of Microsoft's Windows RT, the OS on which Surface runs, to gain any traction at all. One analyst, referring to the platform's virtual absence from the Consumer Electronics show in Las Vegas, said that "Windows RT died in the desert last week."
The rise of the "phablets"
If developers haven't been convinced of the value of responsive design after having to develop websites and apps for desktops, laptops, tablets, and phones, then the advent of phablets ought to provide the final push. Mix with retina displays, and you will find pixel counts and densities and aspect ratios developing into a continuum from pocket to wall.
Benjamin Robbins is spending a year working "mobile only," doing everything from his Galaxy Note II phablet, enabled by local and cloud-based apps. He recently wrote a post opining that we will be better off once the idea of the "phone" dies out completely; it is holding back mobile innovation, Robbins believes. If he's anywhere near right, the mobile space is in for an even wilder ride in in the years ahead.