Although Apple's current-gen versions of its signature iPhone line -- the iPhone 6 and iPhone 6 Plus -- continue to rack up sales to the tune of nearly 140 million units over the past two fiscal quarters, that doesn't mean that Apple's not working on improving the product. 
虽然苹果公司手机线上当前的产品——iPhone6和iPhone 6 Plus在过去的两个会计季度里销量持续增长达近140万台之多,但这并不意味着苹果公司不会继续改进其产品。

According to a report from Bloomberg, Apple's already started working on the next version of its iPhone, going into volume production next month.

And while we're all unsure of the name, the conventional naming nomenclature for phones has been to follow a number change (i.e., going from the iPhone 5s to iPhone 6) with a letter change (i.e. the upgrade from the iPhone 5 to the iPhone 5s), leading me to think the models will be named the iPhone 6s and iPhone 6s Plus.

Again, we don't know what Apple will name the new unit, but it's certainly starting to sound like this will be a letter upgrade more so than a number change. Generally, a number change represents a rather major overhaul, while an off-year letter change generally provides a processor upgrade and user experience upgrade. And Bloomberg confirms what others have been reporting for months: Apple's next iPhone user experience upgrade appears to be Force Touch technology, which can tell how much force a user is exerting on the screen.
再者,我们不知道苹果将如何命名新的产品,但它肯定听上去会更像是一个字母的升级,而非是数字的变化。通常来说,数字的变化代表的是重大的改革,而字母变化通常提供的是处理器的升级和用户体验的升级。彭博社也证实了别家报道了几个月的相关内容:苹果的下一代iPhone用户体验的升级似乎用的是感应力道触控(Force Touch)技术,它可以感应用户触屏时使用的力度。

Furthermore, Bloomberg notes that final assembly is expected to be smooth, as the next phone will be very similar to the current-gen unit. That's dissimilar to big differences, mainly in form factor, between the iPhone 5s and the iPhone 6 or between the iPhone 4S and iPhone 5. In fact, if Bloomberg's reporting is correct, Apple fans may have to bid adieu to smaller-sized iPhones as the iPhone 6 clocks in at 4.7 inches while the iPhone 6 Plus measures 5.5 inches.
此外,彭博社指出,最后的组装预计会很顺利,因为下一款手机将非常类似于目前的产品。这与产品有很大差异时不同,那些差异主要是外形差异,像iPhone 5S和iPhone 6之间以及iPhone 4S和iPhone 5之间。事实上,如果彭博社的报道是正确的,果粉们可能要告别更小尺寸的iPhone,因为iPhone6为4.7英寸,而iPhone6+为5.5英寸。

On the other hand, there are people who prefer a smaller screen. Any time you limit an option, you're taking away consumer choice. If Apple chooses not to release a 4-inch model, it's probably because demand isn't strong enough to justify its continuation, though. In premium smartphones, it seems a 4-inch option is a thing of the past.