I think the only possibilities of new winners this year are Grosjean, Perez, Kobayashi, Senna and Maldonado, simply because:
Grosjean – The Lotus seems strong and I think a podium should definitely happen, might need to be a lot of luck to win though.
Perez and Kobayashi – The Sauber does seem a strong car, but they need more experience of fighting for wins and podiums, with this, I think they can be a force, even in the dry.
Senna and Maldonado – The car, in the race, is quick. This has been shown now in all three races so far, but their Qualifying is dismal. If they can improve their Qualifying performances, podiums could start coming their way, and, with luck, a LOT of it, a win.