Here's what we need. An Instant Messaging program something akin to ICQ for the PC for us WiFi gamers.
The program lets you (optionally) enter your Name/Nickname, e-mail, age, gender, location, etc., etc. Also, it lets you select which DS WiFi games you own (along with entering the Friend Code for that game).
Then you can use this program to IM people to set up matches or "Smack Talk" with them during the match.
But the best part would be that it would let you search for other players based on whatever criteria you want. Say, you want to look for MKDS players in the 18-25 range in the US - It'd let you do a search for that criteria, get a list of people who match that criteria that's currently online, send them a message and set up a game (and, of course, you'd have the option to add/block people to/from your list).
Well, I put forth the idea, who's going to come up with the product?