Gamasutra has received word that Sony is going to make Trophy support mandatory as of January 1st, 2009.

Since the launch of trophy support, games have slowly moved to adopt them as part of their repetoire on the Playstation 3.  But some of the bigger hits have skipped trophies, and some that have patched them in, require you to start the game all over to pick up any of the trophies.

Seeing the need to make the trophy system a draw to the Playstation 3, similar to the way Gamerscore is an inegrated measurement on the 360, Sony has decided that trophy support for games released after January 1st must support the trophy system.  I am not sure what this does to a game that has already finished production work for a post Christmas release, but It should make the Trophy system a better experience overall.