Hearthstone is excellent. I think the Beta is completely open at this point. I applied for a Beta key a few months back, and Agnes did at the same time. She got her key first, but when I got my key it came in an email that said everyone who applied for a key got one.

Sadly, my laptop's onboard graphics chipset can't handle it, so it's just too choppy and frustrating to play. A dialogue with one of the customer service reps pinned down the problem to my hardware. I uninstalled it, but only because it was running at ~2 - 4 FPS.

Agnes has a newer laptop, and it plays on hers. It's a supremely fun game, like a stripped down, approachable version of Magic: The Gathering.