I think if you where in the 11/11/11 beta you can use that one. if you where in the ones before you should uninstall it and use the new download link.
From the look of it, it seems this will be the retail download as well. Install is different and icon sets are different then from the first 2 beta weekends that I was in.
Found the link on
www.swtor.com
I have previously tested Star Wars: The Old Republic and already have the game client. Will I need to re-download the client for the upcoming Beta Testing Weekend?
Yes. The game client has changed substantially since earlier Game Testing phases, and you'll need to re-download it for the upcoming Testing Weekend. If you have been invited to the 11-13th of November Beta Testing Weekend, you will only need to patch the game client for the upcoming Beta Testing Weekend.