The full trophy list hasn't been revealed, but the ones that have been listed so far appear as achievements in the 360 version. 51 trophies sounds like "the full 360 achievement list plus one new platinum trophy for getting all the rest" to me.
We'll all find out together next week, as the patch will be posted for download on Monday, October 27. Like other trophy patches, you won't be awarded any retroactive cups. So get ready to clear out those save games and start cracking.