Well, right now I wonder what the future of the A15 is...?
It's been announced a long time ago, and as far as I remember it was expected that most phones end of 2012 will have an A15 as core.
Every processor ARM has made in recent memory has been announced a good 2-3 years before it has been implemented in anything. That's just how their license model operates. Cortex-A8 was announced in October 2005 and only shipped in devices in late 2008. Cortex-A9 in December 2007, only shipped August 2010. Cortex-A15 in October 2010, shipped in October 2012 (so actually it was the fastest turnaround yet, at least ignoring older CPUs that I don't know much about who shipped first with)
And when it was announced they explicitly said that it'll show up in devices in 2013. It was later revised to late 2012, which is exactly what happened.
Right now, only the Samsung S4 is available, but only some use the A15, others use the Snapdragon.
big.LITTLE and ARM7 were both announced well after Cortex-A15 and were expected to hit quite a bit later. Exynos 5410 came out earlier than I expected it to anyway, which may be why it's so broken.
There are a few tablets or the Chromebook, but they have high-capacity batteries (way more than could fit in a normal smartphone) and battery life is just normal, so I wonder whether the A15 just uses a bit too much power for a phone..?
And the S4 is a pretty huge phone, so it probably has a pretty high-capacity battery as well.
In battery life tests it doesn't do badly precisely because of the A7s. It'd do better if the SoC actually worked right and the OS support was more robust (Samsung isn't great at this). A working big.LITTLE SoC would not be bad for something like Pandora.
It seems only two SoC manufacturers actually finished the A15 for mobile usage. Samsung and NVidia.
All others seem to have switched and only release it for industrial usage.
Two other SoC manufacturers announced A15 SoCs a long time ago: TI and ST-Ericcson. The reason why these didn't come to market for mobile devices is not because A15 tanked for mobile devices but because these companies withdrew from mobile devices completely. Freescale has too. Only Samsung and nVidia are positioning Cortex-A15 for phones because they are literally the only two SoC manufacturers that use bleeding edge CPUs (ie, not cheap Chinese SoCs) that aren't their own in-house designs. That's not A15's fault; although some people like to say that it drove the other companies to make custom CPUs they actually made that decision long before that, some people don't realize Qualcomm has been using custom CPUs for several years. In a couple generations nVidia will be using custom too. So maybe there won't be a market for high end ARM CPUs in mobile platforms period (who knows what Samsung will do), and maybe ARM realizes this and is adjusting their designs to be more useful in other markets.
Of course people always want the most powerful phone - but does the speed in daily usage compared to the reduced battery life justify this?
If you only use it when you need it? Yes. Idle consumption on pure A15 SoCs is fine. Having A7s helps.
I'm not saying this is a reason nor will I say these are facts (I'm not that much into that stuff), but the A15 sure has a slow start right now, especially when comparing it to the start the A9 had.
Selective memory. TI announced OMAP4 would be in phones by the end of 2010, didn't hit until months later. And for quite a while it was just nVidia (who initially sucked because they didn't have NEON), TI, and Samsung. Freescale and ST-E took forever to release theirs, but it doesn't really matter since they're out of the game now. I'm sure Chinese SoCs will start using A15 eventually like they started using A9.
