Double Fine has settled on April 28, 2015 as the release date for Broken Age Act 2 on PC and Broken Age (both acts) on PS4 and PS Vita. European console players have to wait a day.
There's Cross-Buy on PlayStation, and saves are compatible between the two versions.
Not far into Act 1, I became sidetracked with other games and by the time I was ready to pick it back up again, the break had been long enough that it made more sense to just hold off until Act 2 was out. That's the way episodic series tend to go for me these days. Might as well wait.