TSM clearly has the strongest roster on player skill alone. That being said, with that many 'all star' players, it may be difficult to keep them from butting heads.
I think the smartest move was to have Hai switch to support. Support is the least technically demanding role, but is an incredibly good place to put a strategic mastermind like Hai. C9 may be a contender since they should have decent synergy for the most part. Assuming their new player can speak well enough to communicate with the team.
Liquid's team is going to be hard to beat 10v5 ;)
But seriously... I think having that many subs may make synergy extremely difficult, even with the advantage unpredictability gives.
Renegades looked really good in the CS, we'll see if that can translate. Fortunately they have some veteran hands so ego shouldn't be too much of a problem.
TIP is... well, weird. We'll see how they go. Most of their players are relative unknowns so it's hard to evaluate where they'll stand.
NRG has some really strong players, and if the synergy is there could be tough to beat. Altec is still one of the best ADCs around afterall.
Immortals look like monsters. If I had to rank on pure player skill alone, Immortals would be second. Their lineup is crazy. And they've already got the jungle/top synergy from FNatic(poor FNatic losing almost everyone)
Echo Fox... why do teams keep sabotaging themselves by picking the walking ball of ego and bad attitude that is Froggen? He's skilled, although even that is waning, but he's got such an awful attitude that it's no wonder his teams self-destruct. Aside from him, their lineup is mostly fresh blood which can be a good thing but can also be a recipe for nerves.
Dig's lineup is not looking that great. We'll see, maybe they can pull synergy out of thin air, but I'm not hopeful for them, sad though it is since they've always been a favourite of mine.
It will be interesting to see how a team that revolved around their ADC for so long can adapt to not having a star ADC anymore. I'm looking forward to it, because CLG's lineup is still very strong and DoubleLift was far from the only good player on that team, but it'll be a big change for them.