Having participated in the first "speed-dating" event in Chicago, I can say it was a huge success, even though it wasn't necessarily about landing a job right away.
For a lot of us, it was about getting to put a face to the name, for both the SM's and Producers, and the chance to get a vibe from someone in a way that is intangible before an interview. For many of us SM's, we'd been sending resumes to these theatres for years, and it was nice for us to see who was working at those theatres, what kind of positions may or may not be available soon, and to have face to face contact of some kind. The theatre company where I'd been a resident had just folded, so I had plenty to talk to each producer about. I even found that I had worked at some of those theatres before, and there were new people now staffing, and it was nice to introduce myself again.
It was also nice for the SM's, to see each other all together in an event like this, and spontaneously network amongst ourselves. Even though the event didn't land any immediate work for me, I did get contacted months later by several companies when positions became open, and two of those companies have since hired me; one of them seasonally. And I know that PM's are still using those "speed-dating" contacts as a sort of short list to hire people when in need.
I think it's a great idea for other areas to try - I know it can be successful. Good luck!