Plank theme created specially for elementaryOS Luna to match Wingpanel style.
1. Download from: bit.ly/14tpIRm
2. Extract file to 'usr/share/plank/themes'. Should be a 'Wingy' folder on 'Themes'.
3. Open System Settings(Switchboard) > Desktop > Dock > Theme > Wingy.
3. On slingshot search box write "plank --preferences" and hit Enter. Choose the theme on the window that appears