I think many of the author's points are valid, but I do still believe that companies like Blackberry and Nokia can build Android or Windows Mobile phones successfully, as they won't have to deal with a) user inertia from changing to a new OS or b) developing entirely new UI and operating systems.
As far as I can tell, there won't really be any new carriers or any new operating systems, but that doesn't preclude competition in the hardware space.
I hope Blackberry and Nokia can produce some decent phones in the future. Android has come a long way, but Windows Phone is still pretty awful (more importantly, Nokia are never going to produce an Android with Microsoft as an owner). I used a HTC G1 and Motorola Milestone (1.6 and 2.something) as well as a Galaxy S3 (on 4.something) - back at 1.6 it was nothing special, the S3 on 4.x was hugely improved and a joy to use. If I wasn't so heavily vested in iOS it would be a worthy contender. Windows Phone on the other hand I can't say so much for. Most of the people I've spoken to that are non tech-literate don't have favourable experiences. A family member (electrician by trade) had a high-end Nokia Lumia for a year and didn't have a whole lot to say about it, until he took it in for repair and they gave him an iPhone 4S. He couldn't stop talking about how much better he found it to use, and thus as soon as they demanded it back he switched to an iPhone. Until these manufactures delight the user in the same way that the iPhone does, or differentiate themselves enough, there's little hope.
As far as I can tell, there won't really be any new carriers or any new operating systems, but that doesn't preclude competition in the hardware space.