If you develop for Ubuntu and Fedora, many distributions will mostly work with your program : all Ubuntu flavours (Unity, GNOME, XFCE, KDE) and derivatives (Linux Mint, Elementary), maybe Debian, Fedora flavours (GNOME, KDE) and derivatives (Red Hat, CentOS), etc. You'll have to decide for a widget toolkit (Gtk+ or Qt), but a Qt program will run fine on GNOME (the design won't be perfect, but it's like a Qt program on Mac OS X or Windows). Dependencies isn't the big problem : you have a single sound server to look for and other drivers aren't important for a simple program.

Of course it's complicated, more complicated than Windows, depending on your type of program. But seeing how Valve made it work for games, I think it's going to be seen more and more.