before now efven top players could get away with not being the quickest and having a slow serve and one weak shot either their backhand or forehand. in this time to be at the top they need to have a strong serve, they need to be reasonabley quick and they can't have any weakness on one wing. most of the current top 10 at least compared to the rest of the tour have consistent strokes off both sides with power of course there is a difference between venus and serena, #1 and #2 and the #10 but the #10 is still stronger off both sides than most of the rest of the tour.
i'd say in 10 years most players will need to be strong off both sides, be speedy, have a strong serve and be able to serve and volley. basically be able to do everything well and the game probably won't be quite as much baseline as it is today players will probably mix it up a bit more.
Go the aussies! stosur!!!
and good luck russians: dementieva, safina, kirilenko, sharapova, kuznetsova, bovina, zvonareva, dushevina.
also good luck to: azarenka, lucic, sprem, vakulenko, vaidisova, safarova, ivanovic, groenefeld, mirza, krajicek, kvitkova, larcher de brito, lisicki.