According to a rumour picked up by FF-Reunion, Final Fantasy X HD will include X-2 on a single disc exclusively for PlayStation 3.
Final Fantasy X HD is planned for release in 2013 and each game will include its respective International edition content.
The rumour also warns that the PS Vita version won’t contain both titles, you’ll have to pick them up separately if you want to play both.
We aren’t sure if this is going to be the same in the US/EU, the rumour only mentions Japan, but we’ll drop a line with Square Enix to see if we can find out more.