The Mojang team has been rather silent the past week, and now we know why. Tom at Mojang said on his Twitter account, "So, past week we were quite silent as we tried porting the real deal (Minecraft 1.6) to iOS/Android using [RoboVM], but.. nope! Back to 0.8!"To help you non-computer-literate people out there, Minecraft for the PC runs on Java. All Java applications run on top of a Java virtual machine. Mojang tried to make Minecraft run on top of a VM in development for Android and iOS, called RoboVM.
But unfortunately performance was awful. He continued with, "Actually @robovm was impressive and we got MinecraftServer to run on phones quickly.. except MC PC was literally 100 times slower than MCPE! Looks like phones aren't still nowhere near the bandwidth/cache of x86.. and that how people use a language is more important than its JIT!" Maybe one day, maybe one day.
Source: Twitter