The wait is finally over. Blizzard's virtual card game, Hearthstone has officially entered Open Beta! … At least for those playing in the North America region.
The Hearthstone news section has been updated recently with a post confirming the Open Beta, with the journey of Hearthstone over the past year from announcement of the game at PAX East to today's launch being set out briefly before Blizzard invite players in North America who didn't manage to get into the Closed Beta to download the game and begin playing against their friends; assuring them that there won't be any more wipes of the cards accumulated in accounts so they are free to begin building their collections.
The post then goes on to assure players in other regions that they are planning to bring the Open Beta to all over server regions within the next few days, but say that open beta registration might be closed at points if the servers get too overwhelmed by the influx of new players. They also remind everyone that Open Beta is still Beta and therefore they are still monitoring the game closely and things might still go wrong even after all this time.
I can't guess how many new players are going to come into Blizzard's popular free-to-play now that the gates have finally been opened, but I believe the decision to open them region by region is a smart move from the company to avoid too much server overload from new registrations and annoying down-times during those periods when hype is once again at a high for the game. At the very least, I know that an awful lot of people are going to be very excited today/tonight after reading this news.

Blog post is here.