We never know. We don't get advance notice on game releases. The only information we'll likely get is the release itself. Skulls of the Shogun was the only recently-released app where we actually knew that it was coming in advance, really.
I have emailed halfbrick half a dozen times for jetpack joyride! I spent at least $20 on my iPad for this game, I'll spend more to have it on my Lumia.