Consistent? Where? Windows changes its style with each version. Macs may be more consistent, but they're the exception and I never owned a mac. Linux is a rainbow of diversity.
Unless someone puts in the extra effort to style the application, nothing will look consistent cross platform.
And if you want "native, consistent, desktop applications" (for the current platform), Qt has that out of the box and Swing had a native look and feel that looked pretty consistent on Windows 7 at least.
