I own an iPad. It's a pretty device, and it's great for consumption. Browsing the web, watching videos, even reading email - all fun experiences with the iPad. But anything involving typing frustrates me to no end. I hate the fact that the iPad (and on a broader note, touchscreen typing interfaces with no tactile feedback) downgraded me from an extremely fast touch typist to a shitty hunt-and-peck typist. I'm actually faster on my Nexus One than my iPad, because the iPad is too big to use thumbs, but too small to get both hands on like a real keyboard (at least if you have lats), so I end up basically just using my middle fingers.
In the iPad's defense, I don't think it was ever meant to be a productive device. You don't see the people on the billboards reclining with one knee up, typing the next great economics manifesto on their iPads. You see them consuming. Possibly about to raise a finger for a solitary tap, maybe to see another video, or read another email.
But I wish I could be productive with it. I wish I could write on it. I wish I could create with it. But there's no cause for concern - all I see is an opportunity for improvement in this space. There's plenty of room for future innovation in the tablet market, and the iPad is just the beginning. Bring it on.