Samsung has its own OS to bother, so mostly it wont put too much effort to WP, but they are big manufacturer, so it can advertising it.
Sony use android for years, they might switch to WP if it is good.
Lenovo target to sells low end phone, WP is better option because it require less hardware speed than android
HTC got my attraction when it has dual camera, you can take a 3D picture with it
nobody care about Xiao Mi? it would be great if they do a WP, so it can advertise WP to china
but still, im waiting for nokia with 3D touch gesture and nokia lumia 1030. only HTC is my second choice