Comment 71 for bug 1414930

Confirming t450s
Ubutu 15.04 beta 2 latest mainline updates (not the kernel-test ppa)
3.19.0-12-generic #12-Ubuntu SMP Fri Apr 3 04:03:26 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux

Everything working great!
2-finger scroll
middle button scroll
all buttons
keyboard backlight
screen brightness
wifi
external monitor recognized
and no graphical corruption on external monitor

Thanks all for ironing it all out before the release!