Serena is just a better player than she was years ago, she plays the big points better , she plays the percentages better and she attacks her opponent 's weaker serves better.I think her opponents coaching is just as good as before but at this stage Serena isn't getting distracted by the antics of players like the disrespectable Henin, the selfish and drug addict sense of entitlement Capriati or a player such as Clister who could move and be as flexible with her defense to be transferred into offense. Serena's opponents these days are seeing a server that at times can go into a Sampras like rhythm which there's no real answer to her. Being a huge Serena fan and obviously a Rafa fan,I don't see why his camp won't try to emulate her service motions.
Looks like ESPN Sports Science is seeing what I mentioned a few days ago.
http://espn.go.com/video/clip?id=13550350