No, sorry everybody, it's not the Hearthstone open beta--not yet, anyway--but there is a Blizzard open beta that could use your testing clicks. The new launcher app has been in closed beta for some time, but that phase has ended and now it's in full open testing swing. As explained in the official blog post, the new launcher aims to streamline players' experience of Blizzard games by providing a single application from which to access all of them: World of Warcraft, StarCraft II, Diablo III, and Hearthstone.
You'll also be able to use the app to install Blizzard games directly, and if you leave it running it will automatically update those games as well. The new launcher will also allow you to stay logged into your Blizzard games for up to 30 days at a time, if you like. For those interested, you can download the new launcher app here, and access the FAQ here, and you can also check out WoW Insider's overview of what to expect from the new launcher, as well. The app is scheduled to be released in the next few months, in other words, "SoonTM".