I got the same e-mail today. I called them because I had just sent in my new DAT scores and didn't know if this e-mail was in regards to my app with the new scores or the old ones. Here's the basic conversation:
Me: Is this in response to my new scores?
Them: Yes.
Me: So, basically it means I'm not rejected yet, right?
Them: It means we need a bigger pool of applicants to compare applications before we offer any more interviews.
Not really informative, but I think it means we're border-line. Maybe because we're all out-of-staters without 4.0 gpas and 29/29 DAT scores. I'm not sure. But I do know that last year I was rejected without ever getting a "hold" e-mail, so it's a step in the right direction. Not to mention that last year after my rejection, I spoke with Mr. Kim Bryan in order to get some feedback. He said that I was a "bubble player" as an out-of-stater, but probably would have gotten an interview had I been a resident. So let's keep our fingers crossed that we get offered interviews!