We already have something kind of like speed dating for hiring: job fairs. Your idea is more like a one night stand. It would be cool if there were large scale career fairs that are hosted outside of colleges open to the general public, and then there was some sort of organized process where people could talk one on one for some period of time with representatives of the top X companies they choose. Probably will need a basic filter so there aren't tens of thousands of people per company, and spread the interviews out over several days. You always hear about networking, but outside of exclusive groups that already require money or status to be a part of, there aren't opportunities for people who need each other to meet up in an organized way and get things done.

I'm not anticipating you'll read this, but for anyone who happens to read this part of the thread, I don't think job fairs are even close to what I described above. They serve similar purposes, but in my case described above, an actual hire will occur or it won't. Job fairs, at least the ones I've been to are more like an advertising kiosk in a mall where no one you're talking to has any authority of any kind let alone deciding whether or not to hire you on the spot :)

Also, at a job fair you have no idea what the day to day life will be in your new position. In my scenario, once you are or aren't hired you will have already lived the life you will be living if you are hired.