I was in the market for a new MacBook in 2015, but ended up waiting until 2017 for Kaby Lake Y and its upgraded media features (HEVC and 4K and DRM). Plus I hated the keyboard of the 2015 (and the CPU of the 2015 seemed a bit lethargic too).
If I were in the market today, I think I might wait for Ice Lake Y in 2019, mainly for Thunderbolt, but a possible quad core would also be a nice bonus.
However, I have the luxury of being able to wait based on sketchy rumours, since my main machine is an iMac, and I always have other Mac laptops to fall back on anyway.
I wonder what the next iMac will bring