Dunno about you guys, but after reading Kanae's manifesto, I totally loved it. I mean, I was shipping them a bit but after I read that, I saw the potential in them to be the second cannon pair.
I like SasuKarin because it's a nice contrast to NaruSaku.
Sakura is part of Naruto's journey of light and Karin is part of Sasuke's journey of darkness. Sakura has been alongside Naruto as he became a hero and Karin has been alongside Sasuke as he became a villain. NaruSaku is the light couple and SasuKarin is the dark couple.
Even the Summit arc portrayed conflict in each couple. First you have Naruto rejecting Sakura's love and then you have Sasuke betraying Karin's trust.
Look at the ways that Naruto and Sasuke mirror each other:
Pre-stroy:
- Sasuke suffered from family loss / Naruto suffered from loneliness
- Sasuke wants revenge / Naruto wants acknowledgment
Zabuza arc:
- Sasuke awakens the sharingan / Naruro awakens the kyuubi
Chunin exams and Search for Tsunade:
- Sasuke learns lion combo / Naruto learns Naruto rendan (very similar taijutsu moves)
- Sasuke improves his taijutsu / Naruto learns summons and better kyuubi control
- Sasuke learns chidori / Naruto learns rasengan
Sasuke Retrieval:
- Sasuke achieves Curse Seal form / Naruto achieves One-tail kyuubi form
In Part 2 they both improve, but Sasuke has an initial edge:
- Sasuke is generally more proficient / Naruto learns rasenshuriken
Itachi / Pain arc:
- Sasuke fights Itachi / Naruto fights Pain (both with feelings of revenge)
- Sasuke obtains mangekyo sharingan / Naruto obtains sage mode
- Sasuke paves his road of revenge / Naruto paves his road of peace
In the beginning they both share the same path as Team 7, but then form part 2 onwards:
- Sasuke has his team with Karin, Suigetsu and Juugo / Naruto has his team with Sakura, Sai and Kakashi
- Sasuke now has Orochimaru / Naruto maybe will retake Yamato
Kage Summit and Turtle Island:
- Sasuke develops Susanoo / Naruto develops kyuubi cloak
- Sasuke betrays Karin's trust / Naruto refuses Sakura's confession
- Sasuke is said to have changed by Sakura / Naruto is said to be bright by Karin
Ninja War:
- Sasuke unleashes Eternal MS / Naruto unleashes full kyuubi mode
- Sasuke fights Kabuto / Naruto fights Tobi
- Sasuke looks for answers / Naruto's resolve is challenged by Obito
Pairings:
- Sasuke descent towards darkness is witnessed by Karin / Naruto's ascension to the light is witnessed by Sakura
- Sasuke is loved by Sakura / Naruto is loved by Hinata (both girls uninvolved in the journey of said love)