With Minecraft: PS3 Edition set to receive a physical Blu-ray release next month (digital version already available), and plans to release PS4 and Vita versions in "Q2/Q3," Mojang has revealed plans to support world transfers between platforms.
"The plan is to enable users to transfer from PS3 to PS4," said Mojang's Owen Hill when asked if we would be able to transfer a world from PS3 to PS4 or Vita. "We're still working out how it'll work with the Vita version."
Unfortunately, it looks like we'll have to wait on hearing details about possible discounts or Cross-Buy support, as Mojang is waiting closer to its release before sharing information.
"We'll have more news on cross-buy/upgrade options soon! I understand that the wait is frustrating, but we don't want to make false promises," Hill said. Meanwhile, PS3 owners can look forward to a retail disc release starting May 16th. It will include all of the features that came with update 14 on disc, including Emeralds, Ender Chests, potatoes, and more.
[PS Blog]