Laura Robson beat Venus Williams a couple of weeks back and a number of players have been playing with brightly coloured shorts so I can not agree with your POV
Kvitova when on form can hit anyone off the court as can Li Na. In fact there are quite a few big hitters out there in the womens game (including Laura Robson) but it is Serena's more reliable serve that is giving her the strong upper hand right now, though she still wonders away mentally in games sometimes.
Dominica Cibulkova hit Serena off the court for a set and 4-1 up a couple of months back before Serena turned it around
Simona Halep, Sorana cirstea Sabine Lisicki, are all out and out hitters who play an all out attacking game that is, while not consistent, capable of taking the game away from opponenets.