I don't want to have to do a clean install, that's nuts. Why would you not do the in-place upgrade? It would still be free that way, wouldn't it?
It is and will be available from the Windows Store. I agree with you, that a clean install is an absolute harbinger of doom for both myself and many others. I have done it so many times out of necessity, for work, for testing, and for friends and family, that preserving the data is a total nightmare. However, from a technical standpoint, it is the right answer.
While Microsoft has gotten better at their upgrades, normally, people in IT have always suggested never doing an upgrade and always going the route of clean install whenever possible. For every version of Windows, this has very much been the case. And there is a good reason for this.
It almost always takes longer to do the upgrade rather than the clean install, but even if you have to migrate data, you are less likely to experience overhead as you could with the upgrade. You can upgrade all the way from Windows XP to Windows 8, and check it out, I've actually done it:
The problem is that, over the long term, you have a huge amount of unused overhead files, simply due to human error and lack of quality control when each successive version is installed. No one writing the upgrade path from Windows 8 to Windows 8.1 could possibly be thinking or have any knowledge that, in the future, people will be upgrading from Windows 8.1 to "Windows 12" (or something). They may be vaguely aware of it, but they have no idea how that system will operate. When you run a business, you can't just base every development decision on what may happen in the future. And historically, tech companies have focused the vast majority of their resources on developing the software itself, and direct relatively few resources to the installer/uninstaller. This is simply a matter of working with a project that is usually compartmentalized, has a budget, timetables, and milestone goals.
On a computer that upgraded from Windows XP to Windows Vista to Windows 7, and then to Windows 8, we are talking about gigabytes of operating system files that are no longer in use, and extremely difficult to identify; remnants of older stuff.
If you're using Windows 8, you'll probably be able to do the in place upgrade just fine. It will always be "cleaner" to do a clean install. For some people, the upgrade process will take significantly longer than a fresh install of 8.1 would. However, if you want to avoid the doomsday-type situation of having to reinstall all your programs, reintegrate your settings and files, this is probably the best option for the average user.
While a lot of people may be assuming Windows 8.1 is like a service pack, it is not. Many operating system files are going to be changed here, and specifically, if you look at the BuildLabEx number for Windows 8 its:
9200.16628.amd64fre.win8_gdr.130531-1504
For Windows 8.1 Preview it is:
9431.0.amd64fre.winmain_bluemp.130615-1214
That means by this summer, they had probably recompiled the kernel tens of thousands, if not hundreds of thousands of times. When in development, they use this type of methodology to test the operating system against any possible interaction that could stall the kernel with algorithms that test every possible user interaction within the system.
Not to get off topic, but the last update to Windows that replaced the kernel itself was Windows Vista Service Pack 1. I think 8.1 will not be much of a feature pack or service pack as much as it will be an enhancement that addresses many long standing concerns. For me, however, lots of IT buzzwords like "in-place upgrade" don't make any sense. That kind of title suggests that files are simply being copied over and you are good to go. With an upgrade situation as big as Windows has become, hundreds of thousands of files will not just be copied over, but there will be numerous alterations in the code to upgrade to the new platform. Even the most astute computer scientists do not known what proprietary changes are being made when these types of upgrades happen.
This is why from a technical perspective, it is always best to do a clean install, plain and simple. From a utilitarian perspective and a end-user perspective, a quick upgrade is always going to be desired. I, for one, do recommend, however, that if you're using the release preview (which is really a beta or release candidate... designed for paying customers to beta test; another example of buzzwords), you should really consider doing a clean install. Yes, there will likely be a simple upgrade mechanism, and if you can handle that, go for it , but these types of changes, without a clean install, cause unpredictability for troubleshooting when the system breaks down.
In any method of diagnosis, we try to rule out X. We cannot prove Y, so we must rule out X. So when we get down to the nuts and bolts of whats happening here to a system, especially using process of elimination, if get backed into a corner, we can't necessarily rule out the upgrade itself, especially if its recent. "8.1 Preview had been installed for some time" Etc.
By default, we hope for the best that most upgrades will be as stable as the one Microsoft created from Windows 7 to Windows 8, but that is not always the case. There is a small chance some upgrade scenarios for certain types of hardware will not be supported or cause major problems. Even if this is obscure hardware that is, seemingly, not used much, imagine the nightmare when it comes to fruition that this hardware is used by a hundred thousand businesses around the world. This type of scenario has happened before, in the past, and has caused hours of waste in troubleshooting, diagnosis, and support.
We see how this also happened in the transition between Windows XP and Windows Vista, and how a lot of systems were upgraded even though they failed to perform up to the manufacturer's intended specifications. Even though, in many instances, we know that a lot of people who should have upgraded didn't, and a lot of people who should never have upgraded did. So these issues can get quite complex exactly because there are an enormous number of variables that cannot all be accounted for in any given system or operation.