Pricing isn't yet available unfortunately, but the UK model numbers for these ultra-thin sets will be KD-65X9005C and KD-55X9005C for the 65 and 55in screens respectively. Like all of Sony's 2015 TVs, the X90C series will use the Android TV platform.
Due to the slimness of the set, the X90C uses standard downward-firing speakers as opposed to the magnetic fluid design you see on some of Sony's other 4K models. There's also a revised version of Sony's One-Flick control system, originally introduced in 2014.
CES 2015: Sony announces new 4K and Full HD TV ranges
In the flesh, the new range certainly looks impressive, although - technically - the TV isn't 0.2in thin all the way down. Having to accommodate circuit boards, input boards and the other electronics required does mean there's a slight bulge towards the bottom of the set, but even the slimmest OLED TVs aren't immune to this. Take a look at the X90C in action on the CES show floor...
CES 2015: All the latest CES 2015 news highlights