http://cdn.slashgear.com/wp-content/uploads/2010/06/marvell_sheevaplug_1-480x425.jpg
I was looking at this yesterday, it has a really interesting way of working out devices in the home that have been turned on based on the signature of fluctuations in circuit.
I just caught this article regarding new Amahi Home Server:
[url=http://www.ehomeupgrade.com/2010/08/11/amahi-plug-edition-released-brings-amahi-home-server-to-plug-computers/]http://www.ehomeupgrade.com/2010/08/11/amahi-plug-edition-released-brings-amahi-home-server-to-plug-computers/[/url]
and notably, the Stratus that seems to be primed for Zwave and maybe MIOS: http://www.ionicsplug.com/stratus.html
Vera 3 
Revisiting this topic…
Looks like they are on to the next level of Stratus, the Stratus++. That’s right, not one, but TWO pluses.
At $142 I wish I had a job for one right now:
[url=http://www.ionicsplug.com/stratusplusplus.html]http://www.ionicsplug.com/stratusplusplus.html[/url]
Just be careful as you cannot order the Stratus++ model from them right now (although the website leads you to believe otherwise)
They’re currently shipping the original model (in black also) but it’s missing the hard buttons on the top the you would normally use to trigger pairing etc. It still has the ZWave chip, BT, Wifi etc, but the newer model isn’t order able until Summer/Late Summer.
Documentation is also scant, esp for things like where the various (non Wifi) devices have been attached in Linux, but you can largely work it out if you need it.