According to Mass Effect 2 Lead Designer Preston Watamaniuk on the BioWare forums the team is working hard to “offer a smooth progression into ME3 from ME2.” The reasoning is that they “have to have reasonable knowledge” of where a character could end up at the end of the game. So unlike the first Mass Effect, the sequel will not allow players to restart the campaign with all the skills Shepard gained throughout his or her second adventure.

Here is what he officially said:

The short answer is no. The reason is progression. We have been working very hard to make sure we design the abilities system to offer smooth progression into ME3 from ME2. Allowing double progression on characters makes that almost impossible. We have to have reasonable knowledge about where a character could end up finishing all content on a playthrough. We also want to offer choice of character build within specific classes. We replaced that feature with playing after you were done because it preserves progression and allows for smoother downloading of PRC.

Of course, Mass Effect 2 players can feel free to create a new character and start over.

[Via Kotaku]

[Via Joystiq]