Not sure if this is for all WP8 phones, or just my Nokia, but the keyboard is atrocious. Taking up 2\3 of the screen is stupid, and having irregular shaped keys makes it hard to type :(. Comparing it to my old iPhones keyboard is heartbreaking, and even more heartbreaking comparing it to the ipads. Is there any chance this is going to change in the future?
Sure, I heard Nokia were gonna release a 10-inch phone because the keyboard was not iPad-like enough. ;)
On a more serious note, how long have you spent using the keyboard? It has shown to be very good at learning - and honestly you should spend less time trying to hit the buttons and more time just trusting the autocorrect. I probably have a 60% hitrate for actually pressing the correct keys, but at least 90% correct once autocorrect has its way. I just mash on through and trust the keyboard. And obviously go back later and double-check!
I do think the keyboard could do with being maybe a little shorter, but honestly this is a minor issue. I can always see what I'm typing well enough for it not to matter with the exception of badly-coded or badly-optimised apps.