As a PS3 user since its day 1 launch and over 4000 trophies and now day 1 PS4 user, I can say with about 99.99999% certainty trophies will not "carry over." Every game that's been released on both platforms have separate trophy lists. This will be a completely different game, different sku, different trophy list(although same requirements).

What WILL happen if it goes down like other games that have had "retroactive" trophies is for say the 1000 crafts, leves, etc. you will simply have to do one more of those and the trophy will pop. Same with killing mobs, clearing dungeons, etc.

The issue is gonna be the main story completion trophy. There is nothing you'll be able to do short of completing the story again on PS4 with a new character. So the choice will be, log back into PS3 to grind out some possible missing ones or pop em on PS4 by doing one of each and then redo a complete new story playthrough with a new character. I havent decided which I will do.