What Lenovo has done sounds like a smaller deal than it actually is: on the T400 series, the delete and escape keys are about twice as large as normal, taking an odd, long vertical form. As anyone who has used international keyboards can attest, even a little layout or proportion change can throw your typing off. Now why in the world would Lenovo go and do that? USA Today explains:
In designing the new ThinkPad, [Lenovo]installed keystroke-tracking software on about 30 employees' computers (They volunteered). On average, they used the "Escape" and "Delete" keys 700 times per week, yet those were the only "outboard" keys, or non-letter keys, that hadn't been enlarged.
As you can see, this is probably a practical change. The most fascinating thing about this kind of change, though, is how rare it is. Nearly everything about modern keyboards harks back to the early days of the typewriter, from letter spacing to key layout. This anecdote from the article sums up the problem fairly succinctly:
Tom Hardy, who designed the original IBM PC of 1981, said companies have tried many times to change the sizes of keys. That first PC had a smaller "Shift" key than IBM's popular Selectric typewriter did, and it was placed in a different spot, in part because the industry didn't think computers would replace typewriters for high-volume typing tasks. IBM reversed course with the next version to quiet the outcry from skilled touch-typists.
When we're all living on Mars, our spacepods will still have Model Ms. [USA Today]