While Hawke has been my favorite protagonist so far, no, I want a new character for DA4. I don't want to play as the Warden or Hawke or the Inquisitor again for this main story, their time in the spotlight is over. It would be nice if they all show up again like in the instance of a final, epic battle to save Thedas or something, but not as a main protagonist. I found my Inquisitor bland too compared to my Hawke and Warden, but that was the personality I gave her. She's too nice and morally correct. If I played as a blue Hawke, I'd find her just as boring. However, I love all my characters, because I made them have different personalities and make different decisions based on who they were as a character, verses what I would choose if I played as myself.
I gave them their own character development, so they don't start and end as a perfect character that never changes. It is an RPG, so you just need to use your imagination to sculpt around the story Bioware gave us and you will find your character a lot less stagnant.
Now that being said, if Hawke was optional, I wouldn't mind it, but that is a bit too hopeful to think as a possibility. You've got to consider Hawke's LI, a completely different backstory from a new protagonist, and not to mention all the extra dialogue that would need to be made. I really don't see how that would work out, unless they scrap all the mmo fetch quests and focus more on the characters. I honestly would not mind that a bit.