I agree that no firewire is almost guaranteed (and is an absolute deal breaker for me) but I think it's slightly more possible that a non-displayport video out will be offered. My reasoning is that the Mini is marketed as a simple and economical Mac that you have to "
BYODKM: Bring your own display, keyboard and mouse."
So having only a display port video output destroys the majority of the market that the Mini is supposed to be aimed at. Obviously people in this market don't already have a monitor that accepts display port video input, and requiring a relatively expensive video port converter means the Mini is no longer at all simple and easy to just set up and go, and it's now even more expensive when the price is already right on the edge of being too expensive for the economical buyer.
But all of that is not to say that Apple won't do it. It's to point out that it would be another huge misstep in Apple's recent product decisions. For me personally it doesn't make a difference though, because since it almost definitely won't have firewire then there's no way I would buy it anyway.