Ok, here goes my rankings (with reasoning!)
1) Seoul Dynasty
While many would think this to be a painfully obvious choice, I actually don't think the Dynasty are that much ahead of the rest of the league- both Excelsior and Outlaws put up extremely good fights, making every map close. However, as of this moment, Dynasty stands ahead due to their experienced and phenomenal tank/support core (the additions of KuKi and Xepher are also great), but it's the new DPS group, especially the talents of Fleta, that allow them to take the number 1 spot. However, this could change .
2) Dallas Fuel
Despite a slightly underwhelming performance in the preseason, Dallas Fuel has everything it needs to be a league-winning team, and it shows that they were attempting different strategies and comps in their first couple games. I expect them to win many of their games in the upcoming stages in dominant fashion, especially with the new added flexibility of Seagull, xQc, and Custa.
3) Los Angeles Valiant
While many also see their preseason performance as underwhelming, keep in mind that they were without the talents of Agilities and SPACE, two players who have proven to be able to turn the tides of matches in the past. Plus, with Silkthread's endless flexibility, an incredibly strong support core, and a great Korean tank duo, Valiant are destined for some great victories.
4) New York Excelsior
Excelsior and my number 5 team are kind of interchangeable, but I believe Excelsior will skyrocket once they implement Jjonak on the support and Libero on the DPS, with the potential to upset any of the top teams.
5) Houston Outlaws
Same case as Excelsior. They have a great tank and support core, but they need to figure out their DPS situation. Four very talented players, but they need more concrete positions to avoid confusion and incoordination in the future.
6) London Spitfire
I still stand by my long-passionate case of GC Busan falling out, which they've already seemed to do. Profit and Hooreg are strong as ever, but the rest of the team looks lost. If they implement more of the Panthera core, I see them finding more success.
7-10) SF Shock, LA Gladiators, PHI Fusion, BOS Uprising
Simply need to see more of these teams. They all have the potential to be at the top, they all have great players, but with more playtime we'll be able to rank them better.
11) Shanghai Dragons
A rather inflexible lineup, I can't see them making much of an impact this season, especially since they're lacking a talented projectile player.
12) Florida Mayhem
I've expressed my disappointment before and I'll continue to do so. A non talented and a mess of a team. TviQ is obviously still a phenomenal player, but he can only do so much, and Manneten does an incredible job on all his offtanks, but the two of them can't carry the team all alone. Cwoosh is a mess of a tank player, their supports are in jambles, and Logix plays way too passively for the aggressive name he built up for himself. They need roster changes as soon as possible or they'll be staying in this number 12 spot.