As for North America, 4J said, “We don’t have a confirmed North America #MinecraftPSVita release date yet. Hopefully we’ll hear soon.”
When Minecraft: PS Vita Edition launches, it will be free to anyone who owns the digital version of Minecraft: PS3 Edition (retail version cross-buy likely, but unconfirmed). As was announced previously, you should be able to transfer saves between PS3 and PS Vita, with all previously purchased PS3 DLC available on PS Vita as well.
Once Minecraft gets a date in North America, we’ll let you know.