[m_eiman]

Also, why do the OS X and Windows versions look so different?!? The buttons aren't even in the same places!

Different platforms have different conventions and guidelines. Having both versions look and act the same will make it alien on either or both platforms.

[iLoch]

I don't know about that in this case. Take a look at the collapsable menu on the left for OS X and Windows - one has icons and one doesn't. The icons at the top are ordered completely differently by the looks of it. That's not a convention. The real alienation they should worry about is alienating their own users when they're on different platforms. The program should feel familiar regardless.

[m_eiman]

Agreed, it should feel familiar. But also respect the platform conventions. Nobody ever said UX was supposed to be easy, did they? :)

[willtim]

The flip side to this is that is doesn't look/behave alien when you change platform.