Battlefield 3 has been in close beta for a while now, but the open beta was released this morning. It's available FREE to EVERYONE on PS3, XBOX360 and PC. You don't need to purchase the game, preorder the game or anything like that to get access. You just have to download it and play. The site to grab it is:
I'm currently playing the PC version right now. It's a little buggy (as it is a BETA) but I am impressed with battlelog and the game itself feels pretty good. Not a huge jump from Bad Company 2, but the graphics are a little better, I can see there are some tweaks to the control and it runs a LOT smoother on my computer. I'll be giving the PS3 version a try tomorrow. So yea definitely give it a shot, it's free, you've really got nothing to lose except I guess 3GB worth of bandwidth and storage space. It's definitely going to be a big shooter, so get a taste of it before they start charging an arm and a leg for it.