The release date of Broken Age Act 2 has been announced. It will release on April 28, 2015 in North America and April 29 in Europe. It will be released for Windows, Linux, Mac, and will be available for cross-buy on PlayStation 4 and PlayStation Vita. It's unknown if the separate release dates for regions relate to the computer versions as well, since the IGN article makes it seem this way. This is unlikely though since Steam and GOG.com don't have any region blocking for ordering (unless, presumably, required by law), as far as I know. However, even if that ends up to be the case, at least it's only a day.
While you're at IGN, if you don't mind spoilers for Act I and the first part of Act II, they have a video up where they play through the same 12 minutes of the game that was previously revealed, but this time they play through it with Tim Schafer. They discuss what has transpired in the three years since the Kickstarter was announced, the decision to split the game in half and what to expect from the rest of Act 2.