I have some interesting behaviour on this pre release; I figured I should let you know.
pi2 running on Jessie, I followed the instructions (probably missed something) and got as far as rockpool in pre
I attached a dial, gave it a twist and I could see the wave coming from it. Next I attached a rainbow and made hue the output from my dial. I gave the dial a twist and nothing happened, then I noticed the lights going crazy on the dial. I deleted this rule
I started again, this time I attached something to every port. Using my dial I attached it to the matrix graph (I think) but a motor turned on. Using one of the other matrix options I got the other motor to turn on. Gnarly!
It occasionally stops working in pre and works as expected in the old offline.