2015 was long shaping up to be a meh year for smartphone upgrades. With major redesign on the iPhone, Note 4 packing high HD screen and arguably top 2 camera of any smartphone, already fast enough CPU/GPU for both, 50% charging in 30-50 min on a lot of smartphones, 2015 should bring minor performance and feature increases.
I think Adreno 430 is only 30% or so faster than the 420. Smartphones aren't going to evolve as fast as before as they will also keep running into node shrink bottlenecks and power constraints. Imo, the biggest areas of improvement should come in the battery life department but with the focus on thinner smartphones and lack of new affordable battery technologies, I don't anticipate major innovations here.
More or less the more exciting trends are now happening in the budget space with Asus Zenphone 2 and Moto X. Fundamentally the smartphone almost peaked at Note 4/iPhone 6 level. Going beyond that is putting a marketing gimmick 4K screen, 40 megapixel camera, etc. Performance in smartphones is good enough for 95% of people. Even my aging iPhone 5S is still silky smooth and fast, minus Safari reloading web pages due to lack of RAM.
Even 2 years ago when roadmaps were laid out 2014/2015 looked like a meh year for smartphones. iPhone 6's CPU is barely 25% faster than iPhone 5S, a far cry from nearly 2X the increase 5S got over the 5. Since iPhone 6's CPU is arguably the fastest now, we are hitting node bottlenecks / it's harder and harder to get more low hanging IPC / software doesn't scale well to 4-8 cores on smartphones.
The contract business model will make it 'cheap' for a lot of people to upgrade their smartphone every 2 years but honestly now it's all bragging rights or boredom or being embarrassed that you have an ancient phone that causes upgrades. It's just not the same as going from an outdated Nokia E72/Blackberry to say an iPhone/Note. Even the revolution of going from a Motorola V60 to a smartphone was huge. Now, it's just a spec game but the overall smartphone experience has not changed much since Samsung S2/Note 2/iPhone 4S days. It's now a safe bet to easily skip a generation of phone line upgrades and not feel like you are missing out much.
Honestly I can't get excited about smartphones in 2015 - we are basically going to get just slightly upgraded iPhone 6S/6S+ and most phones just catching up to the metal design, screen quality/pixel count and camera quality of the Note 4. It'll still take years before 64-bit software goes mainstream by which point we are talking iPhone 7S/Note 6, or even beyond that.
If a smartphone of the future could stream 4K BluRay quality movies, lossless audio and PS4 level video games directly to your home theater/4K smartTV combo, I would be excited. Personally, to me the excitement in smartphones right now has diminished significantly until we see some serious innovations beyond iPhone 6/6+/Note 4.
I want to plug a smartphone into a dock at work and power a 4K monitor and run a keyboard. Next step is to do all of that wirelessly with multiple displays and speakers. When is that revolution happening?