this is a pretty good point. you look at that list and it scares you, but there's really only two major editions, pro and ultimate. enterprise is the volume-licensed version of ultimate and won't be used by consumers, home premium is the HTPC version of pro. the rest, we won't see on a computer (unless you're a business person or you actually buy PCs from dell or hp). not that complex, when you break it down.
there's still a silly number of licensed names for all that, though.
edit: it's also worth noting that the difference in price between the bottom (available in the us, home premium) and top (ultimate) is only going to be about a hundred dollars. so, based on that, the scale between each edition should only be 20-25$ difference.