I loved Mario Sunshine although there were bits that weren't polished enough. Generally I adored the game though and its summery feel. The Gamecube was a gamers console with a high ratio of games per console sold. The wii for example is more casual and I feel the current userbase of wii u is somewhere in the middle.
Mario Galaxy sold 11 million on a userbase of 100 million so 1 in 9 approx.
I don't think Mario 3D world has a chance of beating Mario Sunshine unless the wii u userbase gets to at least 40 million probably 50 million.
Of course if Mario 3D World gets bundled with every wii u then the figures may be different. If the lifetime sales of wii u only reach 30 million or less I just can't see it happening at all.
The Metacritic rating of Mario Sunshine is 92 and Mario 3D World is 93. Not much in it. Most of my memories of Mario Sunshine are being truly amazed by the game. People claim it was poorly rated but its near identical to Mario 3D. Neither scored as high as the Mario Galaxy games. Both metacritic pages list reviews as low as 60 for both games.
Also Mario 3D World is not technically impressive only visually attractive. Mario Sunshine was technically impressive for its day as well as being attractive. There isn't really a wow factor with Mario 3D World.
I can't really comment on Mario 3D World myself as I haven't bought it yet. Looking to buy when I see the first good deal on it.
Essay Pro