So last night I decided to download and install the Windows 8.1 Pro Preview as I was curious to see if Logan's predictions about the "Start Button" and other features were correct. So far I'm highly un-impressed and Logan was pretty much spot on.
First off, (and probably most crucially) if you are setup on two hard drives, 1 for the OS and 1 for your user profile, when installing Windows 8.1 it will actually move a good portion of your data back to the primary hard drive. It took me 2 hours to install Windows 8.1 (on my Kingston HyperX SSD) because it ended up moving ALL my music from my secondary mechanical drive to my primary drive (which is now pretty much maxed out when it was only 30% before). I wasn't expecting this to occur as I viewed 8.1 like a service pack and I thought worst case scenario it would break the links I had created and generate a new profile on C:. Somehow it actually decided to MOVE (not copy, but move) my data and I'm not even sure of the full extent of what was moved, but I verified the folders that HAD my music are empty and that the primary hard drive now is holding all my tunes.
Second off, the "Start Button" does take you to the Start Screen (no Start Menu). Essentially they just made the whole bottom left corner a button rather than the pop-up hot-corner thing it was.
Third off, every "improvement" really seems to be on the Metro side of things. You can now make "Large" (4 tile) and "Small" (1/4 tile) sized tiles. There are also a lot more settings and better structuring to the PC Settings Metro app. When multi-tasking with Metro apps you can now do more than 2 apps side-by-side and you can also make them take up exactly 1/2 the screen.
So while there are some good improvements on Metro, I don't think this was what anyone REALLY wanted 8.1 to be. Once I get out of work today I will be playing some more with it. If I find any good or surprisingly bad stuff I'll let you all now.