I use the latest stable version of this fantastic file manager, 1.6.2,not the lack of an option if has nautilus
In short: I like a lot folders full of music, open with VLC, for playing around, and what I do with the option to nautilus, open with .... and choose vlc
I think in future versions of thunar would be good to introduce this option to open with .. when you clik second mouse button
Have a look at thunar custom actions: http://docs.xfce.org/xfce/thunar/custom-actions. You can create a custom action to do what you want.
ok thank very much