MJRx9000: Good find...or rather good remembering.
Mario Tennis definitely needs to be online...as probably do all the Mario Sports. Yet, that said IF Mario Golf wasn't online it wouldn't kill the Mario Golf experience.
Speaking of Mario Golf tough, the portable versions of the game have always been pushing the fantasy limits more...and this next incarnation on the console needs to push the Mario universe limits to the fullest. I want most of the courses to have warp pipes, speed arrows, and much more. And actual levels to be designed around real Mario universe locations. A Bowser's Castle course, a Peach Castle's, Yoshi's Island and what not.
Also since we have a cool Mario Soccer game, what should be next? Mario Hockey, Mario football?