As much as I would love to see Roger and Serena win another Wimbledon I don't think either will win another major.
I could be wrong about Serena, but after her US Open loss last year I predicted to my friends that she would never win another major and I am sticking with that prediction. She is currently not in the best shape, as she appears, to me, to be carrying extra weight that is not allowing her to move as well as she has in the past. I also think that she has allowed the attempt to tie Steffi's record to get in her head and she is playing not to lose instead of playing to win. I would honestly not be surprised to see a new number 1 player by the end of the year or early next year, and I would not be surprised to Muguruza as that new number 1.
I would love to see Venus have a good Wimbledon. This is her surface, both because of her style of play, but also because the matches can be kept much shorter by being an aggressive player. Hopefully she and Serena are on opposite sides of the draw this year. She is one of the most elegant movers I have ever seen on the court. Although the all-time most elegant mover on the women's side, in my opinion, was Evonne Goolagong. She almost seemed to be ice skating and playing tennis at the same time. HEY, there is an idea for you northerners!
Will any of the young guns break through on the men's side or will it be Novak and Murray in the final? If those young kids with the big serves can keep their cool mentally they should be ready to do well on the grass.
McEnroe teaming up with Raonic is the most intriguing pairing to me. That should be interesting to watch as they seem to be as different as two people can be.