Is there any GUI(gnome3,kde,xfce etc.) or PPA with an addition to Unity or other GUI userland to have the same functionality as Windows 7? For example- in Windows 7 you can go to a folder with movie files or mp3 files and simply click "play all" and it will automatically open the default media player with all the files added to the playlist based on the naming convention and play them.
rhythmbox-folderview Will help you to play all the music that are in a particular folder.
But the problem is it only applicable to the files that can be played on rhythmbox player.
To install this plugin:(Ubuntu 9.10, 10.04 and 10.10)
To install this the for latest version of Ubuntu you can download the source and install
More info about this plugin can be found here