From the KBS Music Bank website:

[quote]출연자 :
컴백 스테이지 – 강타, 모세
스페셜 스테이지 – 태연(소녀시대) + JOO
뮤뱅 스테이지 – 쥬얼리, 박혜경, 다비치, PDIS feat.메이다니, H-유진 feat.배슬기,
마이티마우스 feat.JJ, 나오미, E.SANG feat.As One, 김종욱, 3rd Coast, To Romance[/quote]

(translation)

Performers:
Comeback Stage: Kangta, Mose
Special Stage: Taeyeon (SNSD) + JOO
Music Bank Stage: Jewelry, Park Hye Kyung, Da Vici, PDIS feat. May Doni, H – Yoo Jin feat. Bae Seul Gi, Mighty Mouth feat. JJ, Naomi, E.SANG feat. As One, Kim Jong Wook, 3rd Coast, To Romance

(translation end)

Special stage with Taeyeon and JOO like everyone was saying. Eh, it should be… interesting. I’d rather hear Taeyeon sing If by herself, but oh well. Looks like SNSD won’t be performing Baby Baby though :(

Credit: KBS + Soshified + SCBet