I think the offensive minded Pokemon got the best gain, which is good because my style is typically offensive.
Now they can use dual stab, one physical and one special. (Rain dance Kingdra comes to mind with surf and waterfall)
Although some Pokemon lost important things to them, such as Sceptile's special leaf blade, most Pokemon gained another attack that was almost as good, while probably getting a lot of other stuff too. Sceptile can still use Energy ball or Grass knot (which is occasionally better than leaf blade, although often worse) while also gaining stuff like special hidden power. Alakazam's loss is without much gain, minus a hidden power, but most offensive Pokemon either got a lot of new attacks that works off their better stat, or got more attacks to make up for some that they lost.
Defensive Pokemon, got hit hard I think. Which is good, because I'm not a defensive player. Now that Blissey has a lot more to worry about, basically every type can hurt her. There are things like Flare Blitz that can make fire Pokemon much more threatening to her.
All considered, I really like the special physical split, and my biggest reason is the physical STAB that dragons get.