Bungie has not said if you will be able to carry the progress that you make in the Destiny beta into the full game when it is released. The developer confirms that they will discuss the specifics about progress at a later date.
The developers wants to dodge the question for now and talk about it later. The not knowing is for sure something that those playing with the beta would like to know, but it is understandable that right now the developers do not know if this will transfer into the final release of the game or not.
Right now it looks like they want to just get the beta test on the way and then see where things lead. For sure it is something that it looks like will be take into consideration later.