You adjust to the keyboard very quickly, a day or two tops, at least on a 10" model. As a long time user of small devices (Sony UMPC, Toshiba Libretto, Psion, etc.) a netbook keyboard feels positively luxurious, and my experience is the direct opposite of yours. I would never do long emails on my iPod Touch but have no issues at all on a netbook.

I have a netbook with Win 7, OS X, and Ubuntu on it, and I use it all the time. There are plenty of times when I need more power than the Touch but don't want to lug my Macbook around, and it also has the virtue of great battery life.