iPhone: "Type What I Mean"

One of the features I'm most looking forward to on the new iPhone is the new "Type What I Mean" (or TWIM, a la DWIM) auto-correction. With TWIM, the iPhone automatically scans your input looking for common misspellings and letter inversions. Yes, I can certainly see where this can be a problem when the iPhone starts correcting things that weren't wrong but I'm pretty sure that Apple is smart enough to include a "learn" feature so your Saduns don't turn into Sudans.