I just got my second Microsoft Natural Ergonomic Keyboard 4000 for my second work PC. A couple years back I started to learn touch typing, and currently this is the best keyboard I can find.
The first thing to do, is to remove F Lock key (optimize :). I do not see any reason to leave this key, if you do touch typing or programming. See below.
The new one I got has Russian letters on it (living near Russia and half of Latvia speaks Russian), and ‘improved’ Windows logo, seems to be from the Windows 8. The downside is, that it does not have bump on the Windows key anymore. See the photos below.
Also, note, that old keyboard letters are dissolving.
Many software developers and programmers prefer this keyboard: