I just saved over my save game. I had just made it over to the second island, gotten all territories in Neon...

I don't think I got a a traditional dialog box screaming at me that I was going to over-rite my save. Whatever happened, I feel like I got kicked in the balls....

...Oh well, at least it's Infamous, which means I can have fun playing it through again...but....damn.

Important question: The game switched me over to Hard mode while playing. What trophy will unlock for me if I finish the game? The trophy description suggests you need to start and end with the same difficulty.

I just started playing tonight... errr... five hours ago.  Saying this game is like crack is an understatement.  It's like crack lit up by Cindy Crawford who then delivers you a nice tasty meatball sub sandwich and a Caribou Lou.

That sucks!  Maybe on your new game save try beating it as evil cole (or good if you already were evil), gotta mix it up! 

So far from most people I've heard that the hard trophy will still unlock if the game switched it to hard and you don't touch it at all.

I beat the game today and I let the game set it to hard for me. So if it sets you to hard difficulty you will still unlock the trophy. I was even messing around the options and accidentally changed it to easy and I still got the trophy for playing through it on the had difficulty.