Very interesting article from AUSGAMERS.com:
http://www.ausgamers.com/features/read/3434451

The one thing that stuck out to me was the info regarding the BETA character:
"AusGamers: ...So what I want to know is, from the beta, have you worked out whether players will be able to carry over their attachment from the beta to final game. Is that even something on the drawing board?

DeeJ: Obviously its something that Im very aware of, that people want to do. Whether or not we can do that, is something that well figure out later. Weve heard the feedback, and we know what its like to create a Guardian, and to love that Guardian -- upgrade it, and give it new gear, and find new weapons, take it to school, polish it up, bring it back to The Tower and teach it some new ways to fight.

You do want to hang onto those things, and we are creating a persistent world where your character is something that you bring with you from activity to activity. So the things that I learnt in fighting the Cabal, I can use when I fight my very good friend over the Internet. As to whether or not that beta character is persistent through the launch, well figure that out later."
I don't think anyone from Bungie has detailed how long the BETA will be and if it will run straight up until the launch of the retail version, but I really do hope they allow you to keep the character you make in the BETA.