There's more than one way to get a better tablet keyboard. Thumb Keyboard (about $2.52) is an innovative, split-tablet keyboard designed to make it easier to hold a slate with your fingers while you type with your thumbs, especially in landscape orientation. It adjusts for all screen sizes, and it's incredibly popular among tablet users. Tablet Keyboard (free) does essentially the same thing, but it isn't laid out quite as nicely.
Swype (free, but the beta is limited) just recently released the 3.0 update to its beta, which will include a special Honeycomb-only, WXGA version for Android tablets, featuring a resizable and movable keyboard. SwiftKey (my favorite phone keyboard) is working on something similar, but that project isn't out yet.