I don't know why people are jumping down the original poster's throat.
Yes, Mac Mini is a nice machine and yes it has a niche in the marketplace and yes there are certain inherent advantages a Mac has over a PC.
All that said, the Mini is long overdue for an update -- even an modest one. It is the only Mac in the current lineup that doesn't have 802.11n. It can only "officially" take 2GB RAM (unofficially 3GB). And the hard drive options are behind the times.
Apple will update the mini soon and then people on this board will be bragging about how much power it has and how much bang for the buck you get. Apple's update cycle is always "lumpier" than the PC world because it is only one manufacturer whereas you have dozens of companies introducing Windows PCs on a regular basis. When we are near the next update cycle the product almost always appears a bit long in the tooth versus the PC competition.
Does this mean that you shouldn't buy a Mini now if you want one? Not necessarily. That depends on your needs, your budget, and your patience. Does it mean that if you already own a Mini you made a mistake or your self-worth is somehow diminished? Of course not. When it comes to computers, love the one you're with!
But I personally find it a bit irritating when people ignore the realities of the computer market, where "faster, cheaper, better" is the law of the land. The mini is a nice little machine, but it will be a much nicer little machine when Apple updates it sometime this spring. I hope they do it sooner rather than later.