Cool MCE
I recently came across this advertisement in one of the magazines. There is a company called Passive Technologies who have released a pretty cool looking MCE machine called lifeStation. It looks like an appliance and still runs MCE 2005; I would recommend to wait when they upgrade to Vista. I don't own one, so I don't have any first hand experience. I also don't know how much it costs, but it is bound to be pricey.
The specs are pretty impressive, it runs a Core Duo Mobile (making it run cooler), supports HD (has both HDMI and HDCP), 750 gb of storage, and is supposed to be "near silent". If anyone has tried it, please drop me a note here with the feedback.