It's an anniversary celebration for the PS2 title which is almost a decade old, releasing in July 2001 in Japan and staggered in 2002 for North America and Europe.
Final Fantasy X stars Tidus on the world of Spira, where he and his friends Yuna and Rikku must put an end to the monster Sin. Square didn't release any images or footage of the HD remake and there was no confirmation of a release for the US or Europe.