How about instead of going the cliché route of "Let's have the players start all over again!" that they have high level enemies that are extremely dangerous so that the only way to clear the DLC is with a lvl 30 character with top gear?
Meh I would rather be stripped then forced to wait till lvl 30.
I have saved all my run throughs right before finishing the final quest, and to be honest only 2 out of the 4 are even past lvl 20, and none are lvl 30.
As for how it looks... It looks great, but its nothing that I can't wait for.
***EDIT***
Also who is the Jack everyone keeps talking about I thinks I missed something.