As of today, at 4:00pm PDT, everyone can get in on the Destiny beta action. This is of course if you have either Xbox Live or Playstation Plus. It does not look like this is open for PC however. If there is word that it will be, we'll update here.
Check out these two articles (Stephen's and Rutledge's) for what we have thought so far on the Destiny experience. These relate to the Alpha, however, but nonetheless should be somewhat relevant. Of course, now you all have the opportunity to go check out Destiny for yourselves, as long as you have the right console(s) and subscription service.
So don't let this opportunity go to waste! Get in on the Destiny Beta before it ends and see what you think about it. It is more or less a demo at this point anyway - only minor changes will likely happen from now on.
As of now, the beta is set to end on July 27th, so if you act quickly, you might get a chance to play the game for a few days and give it a test run. If you are a Bungie fan (a Halo fan), then Destiny seems like it will be the perfect match for you. See if it is all everyone says it is cracked up to be.
Maybe Bungie will do what Respawn did after they opened up the beta to Titanfall and extend it for a few days. That is at least a small possibility, especially if the test on the server load with all the new incoming players doesn't go very well. They may want to do some tweaks and have the high number of player stick around for a little longer. If that does end up being the case, I'm sure many gamers will be happy to get an even greater experience in the Destiny Beta.
Really though, if you are even slightly interested in the game, now is your chance to really test out if you will enjoy it or not.