I also don't know any piano sites like chordie. Teaching piano is still largely the domain of teachers who to teach children and who insist that the kids 'play the notes on the page'.
Here is a link to 'Scott the Piano Guy'. His approach to playing piano is wonderful. You learn basic chord shapes and then how to link them together.
With his approach, all you need are lyrics and chords to play a song - it is very cool stuff. First saw his program on National Public Broadcasting - great show.
"That darn Pythagorean Comma thing keeps messing me up!"http://en.wikipedia.org/wiki/Pythagorean_comma