。
I'll probably be good at skiing next year.
Literal
Next-year [topic-は] well slide-can-[ようになる] [probably-でしょう].
~ようになる ('come to be able to / come to do X') marks a change in state or acquired ability, usually a skill. Often paired with the potential form, as here: 滑れる ('can slide/ski') + ようになる = 'come to be able to ski.' The subject (the speaker) is omitted. Complementary to ~ようにする ('try to / make oneself').