Recently, GameFAQs User YamiJustin posted about a discovery that the Japanese game disks already include English text. With a bit of patching, you can make undub versions (Japanese audio, English text) rather easily.
They uploaded several screenshots and two videos of this version.
The Audio Drama with official English subtitles:
Final Fantasy X | X-2 HD Remaster (ENGLISH) - Audio Drama 'Will' (Full English Subtitled) - YouTube
The first 30 minutes of FFX-2 with a tutorial on the International-exclusive features:
Final Fantasy X-2 HD Remaster (ENGLISH) - Walkthrough 001 - YuRiPa, Ready! Mission Start! - YouTube
Of course, now I'd just like to know why the freaking holdup. Why do we still need to wait 3 months for the release overseas? One can only wonder...
Links to the relevant GameFAQs Topics:
Final Fantasy X | X-2 HD already have official English version on-disc - Final Fantasy X / X-2 HD Remaster Message Board for PlayStation 3 - GameFAQs
Audio Drama 'Will' (FFX | X-2 HD Remaster) - Full English Subtitled (Official)! - Final Fantasy X / X-2 HD Remaster Message Board for PlayStation 3 - GameFAQs
Final Fantasy X-2 HD Remaster Walkthrough (ENGLISH!) - Official English Enabled! - Final Fantasy X / X-2 HD Remaster Message Board for PlayStation 3 - GameFAQs
