So I got my new iPad a few days ago (it's fantastic) and it's reconfirmed a problem I remember having with the iPad 2. By far my biggest gripe with the design is the speaker which, due to the tapered back edges of the iPad, directs the bulk of the sound away from you. But nearly as annoying as that is my issue with the on-screen keyboard. Don't get me wrong--for the most part I really like it. In fact, I'm typing on it right now. But when iOS 5 came out, they added a feature where you can pull the keyboard apart into two smaller half-keyboards, so that you can hold the iPad in both hands and thumb-type like on an iPhone.
Because you can rotate the iPad into either portrait or landscape mode, it's easy to thing of the iPad keyboard as having four "modes": standard portrait, standard landscape, split portrait, and split landscape.
Personally, I love standard landscape. It's nearly as big as a full keyboard and thanks to iOS's autocorrect I can type on it nearly as fast as a physical keyboard. Split portrait is good too, because you can hold the iPad in your hands and type like you would on an iPhone (which I've also gotten quite good at with practice).
Unfortunately, the other two keyboards, in my opinion, are total crap. The standard portrait keyboard is far too small to type normally on, and far too large to effectively hunt-and-peck on. And when using the split landscape keyboard, the two keyboard halves are so far apart that my eyes have to dart left and right to follow what my thumbs are doing, which slows down typing by a lot and makes it very hard to focus on what you're actually writing.
See what I'm getting at? In landscape, standard is great and split is terrible. In portrait, split is great and standard is terrible. Unfortunately, when you switch from portrait to landscape (or back) the keyboard retains its current standard/split status.
So Apple, when you're working on iOS 5.1.1 or 5.2 or even 6, just add a switch in the keyboard settings somewhere that lets us control the splitting of the keyboard based on the rotation.
And fix the damn speaker already.