Basically F-Zero GX with 30 Player online and leaderboards for me. Oh and heavy advertisement, I don't want it dying a horrible death saleswise, justifying another long gap before the next installment.
Which is where the excellence of Nintendo Land comes in. If they pack the game with every Wii U sold, every Wii U owner will be familiar with the series.
...but yeah, some great ordinary advertising to complement that wouldn't be a bad idea.