I've been poking at (tearing my hair out over) DisplayPort support for the various graphics chips under Linux. Rather than post something here that would soon be out of date, I made a status page on the wiki. The executive summary right now is No It Doesn't Work, but that should change soon.
DP actually promises to be a pretty cool technology. Compared to DVI it seems a bit overengineered, but that's sort of like comparing a car to a skateboard. Given the per-port licensing tax on HDMI, I think DP's eventual dominance is inevitable, but HDMI is pretty entrenched so that won't be any time soon. We'll just have to deal with the connector conspiracy until HDMI dies.