We've done this before, with the same group - R'Micha Berger's Aish Das society, which is dedicated to "in-reach" - trying to bring fire to those already in Orthodoxy. It was quite a success.
But - in New York, at least, the word "Shabbaton" no longer seems to mean "religious retreat." It means "singles event." Oh, they happen on a Shabbat and there is programming, but they're primarily for unmarried middle-aged and older adults to meet each other. Even if they seem to be unsuccessful at forming matches. We had one of those in our shul in March, in fact.
And it's getting very frustrating because we're getting phone calls from confused people. "No, it' s not for singles, but singles are certainly welcome and there will be other singles there. No, I don't know how many, because this isn't focused on singles. It's focused on preparing for Rosh HaShanah." Yes the program items are the actual focus of this Shabbaton - how extraordinary. We're getting prominent rabbis and having discussions and panels, plus some less formal things like a dinner and a sing-a-long, but it's not for singles.
My personal feeling, btw? Matches are more likely to occur at an event like this, because the participants will have something other than, "I've been searching since my divorce, but no one is right." to talk about.
However, the discussion groups after the presentations will be sex segregated, so it's pretty clear we're not playing matchmaker. We need to do this - in mixed groups, only the most determined women get to say anything, and there are women who are uncomfortable speaking out in front of men. This way, they all get to participate comfortably. We tried having three groups - one male, one female, one mixed, but we ended up with the m and f groups being too small, and so merging under the leadership of the male leader, and the women in the original mixed group being mostly silent.