Agree with doug that the little skip is an OCD thing which has got markedly worse since the last time I watched her play, and definitely interferes with her play. And who came up with that weird pre-serve ball bounce she does?
Nadal has become virtually unwatchable IMO with his pre-serve routine: pull pants out of backside, pull shirt on one shoulder then the other; touch nose then one ear, touch nose then the other, repeat. It's almost painful to watch, but he is totally gripped by it (and the lining up of his water bottles etc) and he was given 2 time penalties today.