My cofounders and I met through Founder Dating last April. Then we met at a coffee shop to hack out & release a product in 12 hours.. pretty good so far. We kept working together all summer (evenings & weekends) before deciding to move in together for 3 months and start a company (Curebit) together. At the end of those 3 months we had customers & traction, so we got funded by YC. Now we just finished demo day, got additional funding, and are happily growing.
So yeah -- Founder Dating works. If you're looking for a cofounder, check out the Founder Dating event in SF on April 27th. Apply by April 15th.