I spoke with the product manager for the Mac mini today to clarify a few facts.
1. Yes, it will boot headless, meaning with no display or video device connected, enabling you to have what I like to call an iServe.
2. While it is strongly recommended that you only have an Apple Authorized Service Provider crack it open and install RAM, hard drives, Airport and Bluetooth, it will NOT void your warranty if you do it yourself. As is standard operating procedure, however, anything you break while attempting anything on your own is not Apple’s responsibility and will not be covered under warranty. I think that is pretty much common sense.
3. Airport and Bluetooth can, in fact, be added after purchase. AirPort Extreme card and Bluetooth module attach to the Mac mini’s motherboard via a special connector and will be sold together as a kit for $129.
4. RAM is the most accessible upgrade once you get the case off. That much is clear from the picture.
5. All upgrades other than RAM are not as accessible, but accessing them won’t void your warranty, with list item #2 above in mind.
6. The reason the TOP of the Mac mini doesn’t glow and pulse (this is my only gripe so far) is that there wasn’t enough room to light it once the optical drive went in :)
Macintouch has some interesting discussions on where the Mac Mini may go. Some are trying to make it a home server (presumably w/ an external drive, otherwise the wee internal drive will melt). Others note that, despite the absence of various I/O jacks there are an interesting range of firewire peripherals that may allow it to become a media center. Still others speculate that "Asteroid" is more than a GarageBand breakout box, but is a peripheral that makes a Mac mini the center of a home entertaintment system. Ahh, Apple is such fun.