Is that a serious question? Lol of course a new iPhone will launch in 2018.
Apple will make and sell a lot of iPhone X this year and next. They know what they're doing.
Sure is. Also at a starting price of £1,000.00 should they move to a two year cycle? After all, imagine you've just paid that amount of money, only to receive the phone in 2018, the same year the S model comes out. Whats the point?
Many laptops/notebooks are that price or less and you would never consider changing them every year.