The disclosure triangles and combo box look native. The icons, scrollbars, tabs, toolbars, status bar, tip-of-the-day dialog (wtf?), and confirmation dialogs all are obviously non-native, some of them in ways that are trivially fixable (such as getting the button order right in the confirmation dialogs).

I understand that it's pre-beta, but if they consider the current GUI to be even a prototype instead of the placeholder that it is, they'll likely never get any traction outside of Java developers trying to cash in on Apple's App Stores.

> but if they consider the current GUI to be even a prototype instead of the placeholder that it is

I doubt it is. It's not the first Jetbrains IDE on OSX. They may decide to go a very different graphical route for this one as it's pretty obviously OSX-only, but that's not really a given.