No, but a computer expert (who I got to sort out a problem some time ago) explained to me a plausible reason for the 'free' upgrade to Windows 10.JBR, do you ACTUALLY believe ANYTHING is for free?
Apparently, being aware of the widespread negative public opinion of Windows 8, they decided to offer upgrades to their new W10 to all owners of W8 (and W7) for free, mainly to keep public interest and confidence in their products.
When W10 comes out pre-installed on new computers, of course, it will be paid for by the computer manufacturers and also, after the first 'free' year, anyone wanting to get W10 will have to pay.
It is still possible that the suspicions of Microsoft demanding payment for future support of W10 is only that; just a suspicion. So we may yet be pleasantly surprised. Personally, though, I want to know more before I upgrade.