only played the demo, looked quite nice (in a colourful cartooney way) but didnt like the controls, played 2 player with the missus and we kept missing the serves first of all. then realised you had to hold down X / Square (or whatever the control is) was expecting a simple tap of the button, not to hold it down?
demo's 'House of the dead themed' mini game was quite fun, but sure it would get old quick.
nice to see the old sega characters, but maybe this one is for more the younger audience than the typical tennis fan.
Bet its good on the wii (if its released on wii?- criminal if it isnt!

)
5/10 for me