Just to follow up on this, my BTO mini arrived last week (over a week before Apple said it would
). I love it, it works beautifully out of the box - connected to my LAN perfectly, updated itself (it came with iLife 05 pre-installed), and let me ssh straight into my slackware box etc. In the first evening, I had iTunes happily playing my mp3's which were mounted on an NFS share
Most impressive, and on top of all that, the mini itself looks great!
Overall, I'm really impressed, it's a great bit of kit.