No reason to guess, it's already been verified that there will be a new "Sort by Location" for RBN songs. They'll even have their own icon in the list, just like the "1" for RB1 songs, and the "2" for RB2 songs, and so on and so forth.
That's good! I remember being deeply saddened that the Lego icon didn't carry over into RB2, instead reverting to the standard DLC logo. :/