Apple's 2015 iPhone update will purportedly add some features introduced in the iPad Air 2 last year, including an upgrade to 2 gigabytes of RAM and the possibility of pre-installing the Apple SIM, giving users the ability to select a carrier on their own out of the box.

A person familiar with Apple's future product plans, who has provided reliable information in the past, indicated to AppleInsider that the so-called "iPhone 6s," and presumably the Plus version as well, will in fact be upgraded to 2 gigabytes of RAM. Apple has used a single gigabyte of RAM in its iPhone lineup dating back to the iPhone 5, which launched in 2012.

It was earlier that same year that Apple introduced one gigabyte of RAM in its custom A-series CPUs with the third-generation iPad with Retina display. It's expected that Apple will follow the same approach again, bringing iPad memory upgrades to the next iPhone, since the iPad Air 2 included 2 gigabytes of RAM embedded in its A8X chip last year.

Additional RAM would allow iOS to leave background tasks and tabs in Safari open for longer without a need to reload or refresh. But additional RAM can also come with costs to battery life, as memory constantly consumes power.

The same source also told AppleInsider that Apple is strongly considering shipping its next-generation handset with the Apple SIM pre-installed. That piece, which also made its debut with the iPad Air 2, allows consumers to sign up for mobile data plans from any participating carrier directly from the Settings app without long-term contracts and to switch providers at any time.

Such a move would likely meet staunch resistance from wireless carriers, who have forced Apple to scrap similar plans in the past. Even those carriers that signed on to support the Apple SIM in the iPad Air 2 placed limitations on its usefulness when not purchased directly from Apple, and leading U.S. carrier Verizon abstained entirely.

Competition among carriers has been increasingly fierce in recent years, as the airwaves become relatively commoditized and consumers less brand-loyal. Presumably, carriers will be reticent to cede a direct sales relationship with customers, perhaps more so than they were when Apple first floated its virtual SIM idea in 2010.

"The operators are accusing Apple of trying to gain control of their relationship with their mobile customers with the new SIM," the Financial Times reported then. That opinion is not likely to have changed.

What has changed is Apple's position in the market. The iPhone is now the most popular consumer product since the microwave, making it impossible for carriers to ignore.

If Apple does decide to ship the Apple SIM in the new iPhone, carriers are unlikely to eschew support completely — as Verizon has done until now. Rather, the balance of probability tilts in favor of AT&T-style "dedication," in which handsets purchased from carriers would be locked to that network, but those purchased unlocked directly from Apple would be free to pick-and-choose plans at will.