I think the cast is quite okay. I love it that they have lots of "older" people as well, nowadays Amazing Race USA has quite young contestant age average.
Ilmari Nurminen & Aapo Heitula (Dating couple or husbands, Ilmari is a politician in the Finnish Parliament)
They are quite physical and easy on the eye.
Tuukka Ritokoski & Sami Ritokoski (Father and son, Tuukka is a radio host)
They seem fun and one that you would hope to succeed.
Lotta Hintsa & Noora Hintsa (Sisters, Lotta is a model and was crowned Miss Finland 2013)
They are beautiful and sporty. However, Lotta is quite thirsty and goes to any reality show she can ... Boring personality.
Marcus Grönholm & Timo Rautiainen (Former rallydriver and rally co-driver)
Marcus is very big name in Finnish scale. They might be boring but will get audience's empathies.
Jukka Rasila & Mirva Nieminen (Couple, Jukka is an actor and voice actor)
Jukka is a funny comedian, hard to say how they will do in the race.
Anna Perho & Atte Lehtiniittu (Mother and son, Anna is a journalist and TV producer)
Anna gets more and more opinionated the older she gets, but she is still quite likable. I guess they won't last long according to rumours.
Bakari Diarra & Samuel Chime (Friends, Bakari is a fashion designer and rapper)
Bakari is in depths and he has conflicting public image.
Aino-Kaisa Pekonen & Silvia Modig (Friends and colleagues. Aino-Kaisa is a politician and former Minister of Social Affairs and Health, Sylvia is a politician and member of the European Parliament)
I feel like they won't last long. They (especially Silvia) are (or were in their younger days) interesting politicians, but I think they are not that suitable for this format.
Kaisa Mäkäräinen & Mari Eder (Friends and former biathletes)
Physically great, but boring. Likable.
Peter Vesterbacka & Thy ”Anna” Nguyen (Mentor and mentee, Peter is a mobile game developer know for his work with Angry Birds)
Peter is weird ... Somehow I can't imagine this pair going too far.
Janne Lehtonen & Robin Hendry (Friends and trainers on the Finnish version of SAS: Who Dares Wins)
They have great chances to win. Physically and mentally strong.
Katariina Kaitue & Benjamin Harima (Mother and son, Katariina is an actress)
Interesting to see Katariina, because she doesn't seem to be interested on reality-tv, which could mean that she is highly motivated, if she chose to compete in Amazing race. Katariina has kinda intellectual and mature aura, so it's fun to see how she'll be in the race.
My favourites before the season starts:
1. Katariina & Benjamin
2. Janne & Robin
3. Tuukka & Sami
Least favourite has to be Lotta and her sister. We've seen enough of her already in Finnish tv.