For your use there is no special advantage to DisplayPort, and in some future where all video cards use DisplayPort, there is an easy adapter for DisplayPort->DVI so your monitor won't be obsolete.
The only advantage DisplayPort would give you right now where if you where running a 30" or other very high resolution panel, where you could use a single DisplayPort connector instead of two DVI connectors. If you need to play content protected video (i.e. Blueray) you will be far more likely to get compatiblity with HDMI then with DisplayPort, simply because of the rate of adoption.
DisplayPort is mainly positioned against HDMI, and besides the better licencing arrangement, DisplayPort offers a packet based interface instead of HDMI/DVI/VGAs single serial stream of video data. This means a DisplayPort cable can potentially carry several signals at once (for example a webcam built into a monitor wouldn't need a seperate USB cable). It is also of use in eventually reducing the cost of monitors, since it does not require the LCD to have a seperate controller (this makes no difference until all other connectors are dropped from the LCD, so it's mainly laptop LCDs that benefit).
Except for issues with content protected video, or non-sRGB displays, DisplayPort offers no difference in display quality over DVI.
Thanks for all the good responses, I certainly feel a lot more knowledgable about DisplayPort now, and wish I could accept more than one answer! – Sliff – 2009-07-23T18:16:12.933
Well, 2 years later I can tell you that you wrong and looks like DisplayPort is taking shares little by little due to WQHD hi res displays. Instead of figuring out dual link DVI-I, DVI-D for hi res panels, you can just use DisplayPort which is supported by many GPU cards now. PLus you get sound over DP, which is a feature for me since my IPS display has speakers. HDMI is only full HD capable, so no bueno. – None – 2012-12-22T16:32:29.100