I'm not sodding around with this default upgrade option, it's so damn messy. Though Microsoft do say you'll be able to do a fresh install afterwards.
I need an ISO and fresh install.
Same here.
Although I'm not confident they'll make it easy. Windows 8.0 keys are different to Windows 8.1 keys even though that was a free upgrade so despite having a genuine 8.0 key they wouldn't let me install the from the 8.1 ISO, I had to use a workaround using a KMS key to get it to install before changing it to the 8.0 key post-install. For whatever reason microsoft wanted me to do everything through the Windows Store. Pointless and annoying. Depends on how they deal with licences this time around.
The two other things that have caught my attention are that Media Centre won't be available for 10. It wasn't in 8 either but you could get it separately, which I did because it worked well with my TV Tuner card, so I'll have to find something else and XBMC/Kodi looks like a right faff to get working with it. The other thing is that on the Home version of 10, updates are automatic and in the background and you can't change it so it will basically hijack your internet connection at various times. The Pro version lets you delay downloads and installs, and which version you get depends on what you're upgrading from, so be aware.
Finally, on non-genuine versions of 7 and 8, it appears they'll let you upgrade to 10 but they'll leave you with a crippled and nagging version of 10 (watermarks, features unavailable etc) but I'd expect it would still allow security updates as otherwise it would just be a breeding ground for malware to be passed to genuine users. That's just my opinion though.