According to KGI Securities analyst Ming-Chi Kuo - who is an analyst with a high hit rate for being accurate - Apple will make the switch from aluminum iPhone casings to glass in 2017.
Note that this does not apply to the iPhone 7, which is expected to be unveiled in September of this year.
According to Kuo, the move allows Apple to differentiate its smartphone from, well, pretty much everyone else out there who is also using aluminum.
"If iPhone 7 still uses an aluminum casing in 2016, it will be the fifth year in a row that iPhone has done so," wrote Kuo in a note, "which means there is no longer a feeling of freshness to appeal to consumers. Also, a lot of Apple's (US) competitors are also adopting aluminum casings, which means iPhone no longer has a clear edge due to a lack of differentiation. On expectations that iPhone shipments will decline in 2016, we believe Apple will be more strongly motivated to use non-aluminum casings in 2017 in a bid to enhance the competitiveness of iPhone by offering an all-new form-factor design."
But what about robustness? According to Kuo, this isn't going to be a problem.
"Apple already uses glass casing for iPhone 4/ 4S, and non-Apple brands have also been using glass casings. We therefore think a drop test will not be problematic for glass casing."
Weight too is unlikely to be an issue, given the weight saving that Apple would make switching to AMOLED displays, which is also expected to happen in 2017.
"A glass casing may be slightly heavier than an aluminum one of the same thickness, but the difference is so small that the use of the thinner and lighter AMOLED panel will compensate for that."
It's expected that Apple will continue to offer iPhones with aluminum cases in 2017 and possibly beyond, but these are expected to be older models.