I want one and signed up for a waitlist (stayed up until 1 to attempt to buy one).
The reason they're appealing is:
1. Size. Very small, slightly smaller than most cell phones.
2. Decent power. You're not going to be doing any hardcore gaming on it, but it plays back 1080p video perfectly.
3. HDMI output. Related to #2.
I plan on making mine a dedicated television and movie automated torrent system with XBMC on top of it. So basically I will get all my shows and movies "DVR'd" to this machine automatically. What I will need to make this work is:
1. Flash / external storage of at least 64gb. Want to avoid disk-based storage.
2. A script that accepts input through a Web interface / XBMC plugin that will allow me to add shows.
3. A simple script to invoke torrents from RSS (I have already built this).
4. A good bt remote and a bt dongle (this may require a USB hub as well)
So if all works well I can do this for under $100 as well as use it to run emulators and play games from all old systems/arcades without having to deal with buying them from Nintendo/Sony/MS.