This is lke throwing darts at an epileptic fly, but anyway:-
Public vote - no idea.
Jade had to learn a Cha Cha routine last year, to dance for charity, and I think she will love dancing the latin dances so she will kill it.
Chris - He has to work the hips and arms, so no clues from the Tango, but with his attitude and Ola dancing round him, I think he will be the best of the men in the Rumba.
Joe - needs a miracle, or a hypnotist.
Martina - Rumba will be difficult. Her arms looked OK in the Waltz, but I dont know if she will throw herself into it and work her hips. Maybe it will be easier to act lustful because its Matthew.
Lynda - good actress, would have maybe liked the Rumba better, but she can dance and will do a good Cha Cha.
Ricky - I think he will struggle, but he could surprise me. My impression is that he never took to the dancing part of his acting training, but he actually could get the hang of it.
Rav - Will look impressive and give it his all. Having Aliona to dance with will help, and he seems to be able to use his arms, but can he work his hips? (Tip for Rav, not just side to side, you stir them in a figure 8)
Ali - Can dance, easy.