Nice review - as others have said, pretty straight on, and unbiased.
I picked up an Apple TV on Thursday (N Michigan Ave store has a rotating stock of 27 in shelves where some useless iPod accessories used to be), and have loved it. I have a 30" CRT Toshiba HD monitor with HDMI, so it looks great, even with 640x480 iTunes downloads. CRTs tend to not look as sharp as LCDs anyway, which in this case, makes the picture better looking. The lack of surround sound is a downer, but I don't have much in the way of surround sound capable files (only DVDs), so not a biggie yet.
The thing that bothers me so far, though, is that the one thing that seems most unfinished is the one thing Apple always gets right - the software. The hardware is spot on - HDMI and optical audio will be future-proof for some time, and 802.11n flies (even when streaming from my three year old PowerBook G4). Sure, the interface is great, but codec support, surround sound decoding, full 1080p, etc. are all more than possible with the hardware, just not implemented. I'm sure part of the reason is that you're supposed to use iTunes only in Apple's view of the world, so the best video you have is 640x480, which scales adequately to 720p, but not so much to 1080p. And streaming full HD would mean you'd have to have 802.11n on both sides - and few have a Core 2 Duo Mac (or PC with n) and an Apple TV at this point. Integration is a big thing for Apple, so adding features that a majority of the population would have difficulty using is not usually their thing.
The whole thing reminds me of the initial iPod, but with one huge difference. These shortfalls can be fixed, quickly, with a software update. Maybe there's some very cool features hiding in there waiting for Leopard/iPhone (Safari? iChat with a USB iSight? iCal + Apple TV + iTVGuide + IPTV? iPhone as a remote with chapters and such appearing on the iPhone while the main video plays on your TV, so you can preview which chapter you want without stopping the current video - wait, I should patent that or something).
Even without the usual "hacks" this box packs all the hardware it needs to be relevant for a number of years without a significant hardware refresh. I'm really looking forward to Leopard/iPhone/the first software update.