Amazon Kindle, Amazon.com's new proprietary-store-backed portable e-book reader and audiobook player. No computer required for books, it gets data directly from a subsidized cellular network (Sprint's EVDO network, no subscription required). You can email documents to the device, but it only supports MS Word, plaintext and a few image formats, no PDF. Emailing yourself a file costs 10 cents, which makes sense since you're otherwise not paying for cellular data transfer. It does have a USB cable for transferring audio books, and it looks like you can't use it for other file transfers. It also has an SD card slot for expansion, though I'm guessing you can't use it for shuttling files either. You can access Amazon.com over the cellular connection, or Wikipedia (for free), but it's not a general purpose browser.
The business model is restrictive, but since freedom is exchanged for convenience, it might work. I'd compare it with iTunes if it weren't for the lack of PDF support: iPods rose to power on a widely adopted standard format, MP3, which is still an essential feature of the device even with the popularity of the iTunes Store. It looks like Kindle's layout engine isn't powerful enough for PDF, and plaintext doesn't have the same utility. I'm not that keen on paying $10 a pop for e-books that go straight to a device where I can't access, back up or manipulate the files. (You can re-download files if your device breaks.)
That $400 price tag has to go. A device like this ought to be less than $100, or include a lifetime supply of books. I'd pay $400 for a quality reader with free file transfers and PDF support. I'm tempted to assume Amazon will drop the price to $199 within a year, but that may just be because the device looks cheap, and the terms suck. Then again, full-featured ultra-portable laptop computers are already this cheap, so that's gotta be a forcing factor.
I also doubt a company like Amazon would iterate on the hardware unless the business model is a home run, and it won't be with their terms and selection. And the longer they go without improving the product line, the more likely they are to ditch it altogether. And when they ditch it, everyone who bought the device and paid for content will lose all the books once their device dies, if not sooner.
Overall, what's exciting about Kindle is what has always been exciting about the idea of an ideal e-book reader, and the technology combinations we've been talking about for years: electronic paper, wireless data, low-power portable devices. That excitement evaporates pretty quickly when you discover Kindle isn't anything like an ideal e-book reader.