I'm a big fan of Mario Tennis (N64) but never really liked Mario Power Tennis (GC). They'd have to change a lot more than the controls to get me to buy it.
I was very much the same way for a while, and then I started to realize that the only part I really despised were those stupid Power Shots. They just gave the computer a crutch to return some of your best shots and as a result extended matches to ridiculous lengths.
However, given the ability to turn the nonsense off in the non-tournament mode (where I spent the most time playing with friends anyway) I found myself enjoying the game much more. It felt pretty much on par with the 64 version, though both definitely have their own feel.
I'm curious to see if the motion control actually makes the game anymore fun. It always seemed like a game that was too fast paced to effectively feature such controls.
But anyway, I liked the video, and from the quick glimpse I got of both the disc arts, it looks like Nintendo reused those in addition to the reverse-side box art, which I found interesting.