I don't really play piano, but I'm learning keyboard! I mean, it's obviously different than the piano, with the latter being an acoustic instrument (I heard it also has pedals and stuff), but in the matter of learning the keys, chords, scales and whatnot, it's pretty straightforward. Definitely easier than guitar from what I can tell.
(I desperately need to practice more, though. My skills are terrible and I'm taking classes from... 5-6 months now? I know how to play Happy Birthday to You, at least :P).