Developer PopCap made it known that the game was in the works last August, but just today posted a teaser video on YouTube stating that the game will be launching in July. The video doesn't show any gameplay, or give any information about the game at all actually. It just shows users who are angry that the Plants vs Zombies sequel is taking so long, which seems to be why PopCap has decided to subtitle PvZ 2: It's About Time.
There's also no word on what platforms will be seeing the game first, if it will be a rolling release on different platforms, or if it will launch everywhere all at once. We should be finding out more soon enough, since the game is set for release in just two months.