Most Netbooks have ridiculously small keys. The MSI Wind's alright, but the eeePC is kinda uncomfortable to type on.
A tablet is clearly not meant to be for typing, it's a computer you can use while standing. While some people excel at typing one handed (I know this guy, he rests his thumb nuckle on the space bar and types with the 4 fingers of the same hand. He's faster than me touch typing), it's hard because you still need to balance the laptop on one hand. I'm rather fast and accurate when typing standard text on my iPhone, actually.
When you're normally surfing the web, you mostly scroll and click. Auto-Completion of URLs and search terms works well nowadays, too. If you still need to take notes quickly, just dictate it into the microphone and type it out later, when you have access to a keyboard.
When you're using iLife, you barely need to type stuff. Maybe the name of a new project or iPhoto event.
Using forums, chat and e-mail might get annoying, not as bad as on the iPhone, but still.
If there was a dock or stand to get the thing into an angled, laptop screen position, I would actually be interested in a Mac tablet like this. On the other hand, my life is on my Macbook. Performance is sufficient and I can do all I need to do on it. Will get a new one though just for Snow Leopard and the backlit keyboard.
