Unfortunately the most of developers, who are developing software for Windows and for Linux, concentrate the main power on windows applications. For example Skype offers their software for different platforms, but only Windows based version has all new features.
The reason of this behaviour is a dimension of windows community.
The one of good exception is a Google Earth 4.0. Google released all versions of their software at the same time.
The main new feature of Google Earth is a new possibility to view famous buildings in 3D view.