Here is a fact I don't know if people realize... The mac mini is the smallest computer you can get for $599 period. There are other small pc out there but for some reason they are super expensive. Even if you did get a small pc it doesn't run OS X.
The mini is the best micro pc to date. Its upgradable, silent, cheap and looks cool and there are tons of accessories for it.
Long live the mini.
I totally agree. I recently bought a new PC (tried to go for a "cube 2" feel), and I ended up paying through the nose. I payed 5400 aud (~4400 usd, I think) for e6700 (2.66 ghz C2D), 2 gigs of ram, 500gb hdd, 7950gt, superdrive (or whatever - it can handle everything except HD or Blu-ray disks, reading and burning). I also got a nice acd 23", wireless, bluetooth, nice sound card etc - all the trimmings. I'm still struggling with getting it up and running. I'm plagued with heat and noise issues that I will hopefully be able to resolve.
Bottom line is you CAN have a beautiful mini (or cube) replacement in the PC world. You could even conceivably run osx, if you had the piration skills. Be prepared to sell most of your internal organs and some of your limbs for what you get. Sanity might go, too.
The mini takes the hassle out of all of this. Some PC manufacturers (I'm looking at shuttle here) come close, but it's still not wonderful. In the computer world small will always attract a price premium (my motherboard, for example, was nearly aud600 even though it's fairly low end). Since apple now has to buy the same things as everyone else - not to mention has to develope their own motherboards etc - they have to obey whatever the market dictates. Their high volumes help a little, but when you look at price vs performance for most of the innards you can see that there are massive issues.
If people are saying the mini is too slow then they obviously don't realise what is inside it. It's not designed to be fast, it's designed to be small, cute and quite. Want fast? Go buy a Mac Pro - or better yet, shell out for that ultra expensive Dell.
/rant