First off I agree with everyone who thinks you should delay until it has been out for a few months. There are a lot of machines and software combinations out there that it has not been fully tested with.
As far as my opinion, I found it to be far better than Windows 7-8.1. I thought it was much more functional, and placing the 8 startmenu inside of the traditional - therefore never leaving the desktop was a good fix as far as going along with the designs they have, and also pleasing the consumers.
Windows 10 is coming with a lot of new components built in that would usually be aftermarket, such as virtual desktops for more work space. I have caught wind from my professors that Microsoft has been informing them of new software coming out, and they claim to be incorporating Linux platforms into things such as Visual Studio.
With some of the recent bugs popping up in 7, and the end of XP support, I think many users will soon be forced, to some degree, to upgrade - more than they ever had to in the past. 8 and 8.1 were far more messy than 7 in my opinion, but possibly not as bad as Vista. The Windows 8 machines I have been around lately have been largely problematic, and they get infected with a very large amount of viruses compared to other machines as far as I can tell.
As far as myself, I would only use Windows 7, or 10, and once 10 has come out it will be my go to Windows system - though, I am an amid Linux user, so I do not rely on Windows as my main system. I liked Windows 10, and it gave me a feeling like they were really trying to make it how consumers wanted it versus how they wanted it.