It's possible. Depending on whether Sony and Square are going to put their eggs in the porting basket for this or others (including Radiata Stories), we'll have to wait and see whether they actually do it. However, the classics for some reason aren't ported in massive supplies. At most it seems they only bring over one PlayStation 2 game to the store a week. Does Sony think gamers can't handle more?
Thank you for your input mooserocka, but you are misinformed. A lot of games that have been ported for release in regions outside of Japan have been changed in the process. Some games have songs or voice clips in them that were recorded in other countries so that the dialogue can be understood in those regions. Those songs or voice clips are the intellectual property of the people who performed for the recording.
When a game is brought back for release they either have to change the game to not include that content or gain consent from the people who helped in the development, otherwise they can face lawsuits. This requires a lot of money and time. You are probably more likely to see some of these ps2 greatest hits remade, in HD, in disk form, than to see them on the PSN. Square Enix has already re-released a lot of their older games, and they are on FF10/FF10-2 now, so SO: Till the End of Time will probably be skipped.
Japan is a whole 'nother country. There are different rules between here and Japan. For instance, is it worth porting? Will people buy it enough for it to become more profitable than anything else they could be using their resources for?