Hey there,
I've had Tennis Elbow for 6 years, and I've come to the point where I love it so much, but the AI is the same and I don't like PvP, since it requires online and I enjoy playing in my own little universe more than competition, which tends to rile up my emotions. x__x
I want to Mod the AI. Really Really badly. Otherwise, I'm thinking about programming my own tennis video game...
The second thing that I want to mod is physics, and bringing stats even higher than 100% on the computers. This way, the players could really feel different. I want to bring Nadal's spin up to 130%+ and make a court that has really light physics.