For the year that he has had, Yukinori Oguni definitely deserved a mention. I can't gauge what level he will reach - I've only seen one of his early fights, a struggle with Eric Rapada - but successfully defending the equivalent of the European title against three solid opponents (especially the world rated Serie, who he dominated according to reports) is very impressive. Plus, he has only had ten fights!
Others from Japan to watch out for in 2013 include Naoya Inoue, Ryosuke Iwasa, Sho Ishida, Kenichi Ogawa (interesting to see how he'll bounce back from his first loss), Kyotaro Fujimoto, Tomoki Kameda, Kenji Kubo, and Keita Obara.
Thailand has a few guys coming through as ever. Jomthong Chuwatana is the standout, due to his rapid progression and Muay Thai background. He has only had four fights, but looks ready to challenge for world honours next year. Amnat Ruenroeng, a talented former Olympian boxer, is another guy being moved along fast (although that is mainly down to him being 33) and one to watch out for. I also like the look of Teerachai Kratingdaenggym, a 20-year old welterweight who also comes from a Muay Thai background.
From the Philippines, I've been watching Froilan 'The Sniper' Saludar for a long time. He only made steady progress this year, but I believe he is highly ranked by a few governing bodies so it'll be interesting to see how they move him in 2013. I wouldn't label him as a prospect, but Denver Cuello is, arguably, the best current Filipino fighter not to have challenged for a 'world' title. That will change next year when he faces Xiong Zhao Zhong, a fight he should be a big favourite in.
I don't really follow the African boxing scene too much, but Zolani Tete is a talented fighter that I like the look of despite him losing three of his last six contests. I've seen Bongo Lipembo receive quite a bit of hype, but his career seems to have stagnated despite talk of him fighting in the USA this year. And Thabiso Mchunu won the Super 8 cruiserweight tournament in South Africa this year, so he is worthy of a mention.
Others that I'm watching include Wale Omotoso, Jack Culcay, Fedor Papazov, the Arroyo twins, and Carlos Ivan Velasquez.
Err, sorry for going on...