http://ps3.ign.com/articles/117/1170993p1.html
If you beat the original Infamous, collected the 350 blast shards, and earned the Platinum Trophy, chances are you'd be down with Infamous 2 rewards based on those accomplishments. Developer Sucker Punch agrees.
When you boot up Infamous 2, you'll see an option that says "import Trophy data." By selecting it, the game will read your online Trophies and give you access to the following perks if you meet the criteria.
Have good or evil Trophies from Infamous: Start Infamous 2 at level 1 good karma or level 1 evil karma.
Infamous Trophy for 25 percent of the Blast Shards: Free energy core in Infamous 2.
Infamous Trophy for 50 percent of the Blast Shards: Two free energy cores.
Finished Infamous with any karma standing on any difficulty: 1,000 bonus XP for Infamous 2.
Specific Trophies for Specific Infamous decisions: Reflect side missions, Dead Drops and dialog variety in Infamous 2.