Personally I don't care so much about race selection. What I do care about is having a protagonist that is fleshed out and real. I love the DA games, but to me Hawke was the only protagonist that seemed to be a real person. The Warden and Quizzy ... just lacked a rich personality IMO. Even picking different backgrounds in DA:I did not add to feeling the protagonist was real. She was kind of bland IMO. DA:O did that much, much better.
I guess the games like Uncharted and TW have characters that are so well defined and well written that it brings a level of pleasure and soulfulness to the game playing that I would love to see in the world of Thedas. I wonder if that is why so many people would love to see their warden back? I wonder if that is why people are so curious about what happened to their companions - from Oghren to Fenris to Merrill (ok maybe not Merrill LOL).
So in addition to the usual DA:4 new protagonist - a new series focusing on a story of one protagonist (ideally Elven or Human based on my preferences of course) would be welcomed by me. I would love to see for example, the story of an Elven Rebellion build over two or three games with the same principal characters. ....
Oh well .... 
I pretty much detested Hawke because there was way too much about him that was already set in stone. Its the same reason I don't like Geralt as much as I probably should, even the decisions I make are limited by his already pre-determined scope of the world he lives in.
The Warden is my favorite of the three because he was pretty much a blank slate, I could put my voice to his words and hear me saying them. They kept the background entrances short for that exact reason, you got a basic "You're an elf from the Wilderness" or an "You're a dwarf and this is why you're stuck on the surface now" and were free to fill in the majority of the blanks yourself as you went along.
I got two games with the Warden already, Awakening is long enough to be its own game considering the downward spiral of game times in the recent years. Would I mind seeing him again, no, but would I want them to build a brand new game just to say "Your hero is back" not really. One: I like my Warden as he is and the World of Thedas has certainly changed him in my absence in his shoes and Two: they would still have to find a way to fill those shoes for people with deceased Wardens or by plot convenience bring him back in a fashion similar to Leliana or Anders.
The problem with having a set in stone protagonist is the amount of plot armor that character has to have to continue to a sequel; Hawke for example is put in situations that the Warden would have said "I'm going to die here" and actually die with an ending sequence where as Hawke had plenty of moments where he should have died but the plot dictated Deus Ex Machina would appear to save him. I really wonder what would have happened if we spent all that time building Hawke to have him/her die by the Ogre and we were playing Carver or Bethany instead; similar to the bait and switch swap MGS2 did with Snake and Raiden.