Okay I'm going to take a guess at some of the celeb housemate types I think TPTB will be looking at casting. I think who they cast will really depend on whether the show is pre-recorded or live. If it is pre-recorded, I think they can afford to have some higher profile stars in there (atleast in Ch7 eyes, such as current Home and Away cast members), but if it was live I don't think this would be as feasible.
Let me know who you think would fit under these categories, or if I've left a housemate type off the list.
Older controversial/conservative Housemate
My guess - Steve Price
Young Male Eyecandy/Influencer
My Guess - Josh Heuston
Young Female Eyecandy
My Guess - Shanni Grimmond
Ex Soap Star
My Guess - Luke Jacobs
Ex Reality Star
My Guess - Angela from BB or Martha from MAFS
Singer
My Guess - Katie Underwood or Christine Anu
Flamboyant/gossip housemate
My Guess - David 'Robbo' Robinson (I would have said Joel Creasy but he has radio commitments)
90s Star Throwback (for that I miss my kids/where are they now moment)
My Guess - Bruce Samazan, or Totti Goldsmith
News Reader
My Guess - Sam Mac, Naomi Robson or Jessica Rowe
Comedian
My Guess - Anne Edmonds