That's because Apple will be licensing the Mini DisplayPort specification for free, meaning Apple might not be the singular assholes to use it (which is why their shrunken variations on DVI, while not technically proprietary, practically were). At the very least, even if vendors like Dell—an early supporter of DisplayPort—don't pick it up, it should mean a decent-sized ecosystem of Mini DisplayPort accessories, not just a handful of adapters and a pricey monitor that Apple's given us so far. How about a MDP to HDMI and MDP to DP adapters, for starters? [Ars]
See, the problem is not the fact it's DVI, the problem is not the fact that it's mini. The problem is that you always need to carry around 2 adapters (Which cost extra) at all times if you actually want to use the port.
So i say boo. Just put a regular DVI or VGA out and forget about the adapters. However, as we all know, Apple needs to be "different". I.E. make you pay more than you need for useless stuff.