I've been using a CR-48 for a few days, and I don't think this type of platform is a Windows-killer. But it fills a huge hole in my life - I finally have a computer with a cell connection AND a real keyboard. Tethering my laptop to my cellphone was the best solution I had. This was awkward, especially in tight places like trains. And phones and tablet interfaces are great for reading, but when I type, I want to type at full speed. The Great American Novel will never be written by pecking letters into an iPhone.
If it had a reasonable way to code, I would abandon my laptop altogether.
You realize you're $20 away from having a cell connection for your laptop, right? That's how much it will cost you to walk into your nearest mobile phone shop and buy a prepaid USB dongle. And it will come topped up with a month's worth of data.
You can data by the month for $15 whenever you need it and (depending on your network) get the added bonus of having unlimited access to every paid wifi hotspot in the world for that month.
Definitely worth keeping one of those in the laptop bag for the times when you can't find a good coffee shop or an AP named "Linksys".
Actually, in Japan, a bunch of novels are written on phones.
Also, if you hit C-A-T on the cr48, it opens up a terminal. Have fun coding. Though, it works best if you ssh into a VPS or some other machine since you are limited on what you can install.
If it had a reasonable way to code, I would abandon my laptop altogether.