After originally suggesting plans for a new EP, Sum 41 has announced that they will be releasing a new full length in 2009:

There was talk about doing an ep and then that turned into other things. Next thing you know we're sitting here with a whole bunch of songs that we really like. So instead of doing anything else we've just decided to go and make a full album. As to when it will come out, I don't know. I would say it's safe to say it will be out this year. unless for some reason we need to keep going and it pushes it back further.

The band released Underclass Hero in 2007.