I believe the new trackpads on the new MB and MBP do not have a click that actually presses down physically, but the tactic engine can simulate a clicking feel that is almost identical to mechanical clicks.
from the new macbook's description via Apple: "The Force Touch trackpad is engineered to deliver a responsive, uniform click no matter where you press the surface."
so along with the keys that have a similar uniform click 'no matter where' you press on it, this thing is going to feel very different, at least at first. i hope it's ok, cause the difference between my '10 mbp and my '13 rmbp is very apparent. i happen to love the rmbp but a change that drastic in the opposite direction could mean trouble for me if this is apple's future (some critics who've tried hands on have already claimed they hate it). definitely anxious to try it out at the store soon.