FYI, for those who do not know. There is a site called Microsoft Expert Zone through which there seems to be an unlimited number of beta codes. You'll need a US Proxy if your outside of the US (I used a program called HotSpot Shield), plus a valid GameStop store (use the store locator on their US website) to get the address and store number along with phone number. It also requires you to have an active hotmail account, but I would recommend creating a fake one that's not attached to your gamertag which you can do after you select your region (select US) on the website. Just make sure you select the newbie option that sets up both a hotmail account (make sure its US based) and a Microsoft Expert Zone account.
I am currently DL'ing the beta thanks to this method. If anyone needs better instructions I can write out a better list.