After early indications from the playable demo of Final Fantasy IV and Chrono Trigger, signs point to updated translations for both games. Final Fantasy IV sports a brand new translation, and after playing Chrono Trigger, signs point to an updated translation. For example, at the beginning of the original Chrono Trigger for the SNES at the beginning when Crono is awakened by his mother, her default name is Crono's Mom. In the new Chrono Trigger, she is simply "Mom." As you can see, the translation has been altered to some degree.
When asked about compatiability issues with the PlayStation 2, the offical answer was "It will be compatible with PlayStation 2." However, glitches do exist, such as problems with the dash button and the music tempo with Final Fantasy IV. Currently there are no reported problems with Chrono Trigger.
When asked about the re-translation of Final Fantasy IV, a Square representative commented that classic lines from the original translation will remain, such as "You spoony bard." Cheesy lines never die.
RPGFan will keep you updated as we learn more about Final Fantasy Chronicles.