I like it. It took me a few takes, but I like it.
The round shape is a contrast to the screen, which is good, and it is also a "weaker" shape, which is good: The base should not be attracting attention to itself. The focal point of the computer is - and should be - the screen, so it's a good idea to allow the eye to slide off the curve of the base. Also, the round shape looks more like a weight, emphasizing the floating quality of the screen. It looks tethered. Finally, round shapes are (generally) perceived as organic, warm and unintimidating.
Functionally, this design is also an improvement. The original iMac's screen was too low for a lot of people. The new iMac seems to have a far more adjustable screen height and angle. Others have pointed out that Apple can easily update this design to offer bigger and/or denser screens, which is good, or to make it detachable if it is not already (which I doubt, but we'll know in an hour).
Yes, it looks like a piece of furniture. That's perfect. You can put it right in the living room instead of hiding it in a desk in a back room. It would go well in an IKEA household, true, but it would also fit into a Target household - lean, clean designs are fairly common now. And white goes with just about everything.
I still think the Cube is the most gorgeous computer Apple has ever made, but this ain't bad. Like all Apple designs, it probably looks a lot better in person.
This might be what gets me to an Apple Store.